Wiley: Plant Biotechnology Journal: Table of Contents

Ectopic Expression of ScALDH21 From a Desert Moss Enhances Cotton Resistance to Verticillium Wilt via the Modulation of Jasmonates and Phenylpropanoid Pathways

Tue, 28 Apr 2026 00:13:12 -0700

ABSTRACT

Biotic stresses, particularly Verticillium wilt (VW), lead to a global decline in cotton yields. Here, we demonstrate that ectopic expression of ScALDH21, a gene from the desiccation-tolerant moss Syntrichia caninervis Mitt. and absent in angiosperms, enhances cotton's resistance to VW. Multi-year, multiple location field evaluations showed that transgenic cotton lines consistently exhibited two major advantages: markedly improved resistance to VW, and significantly reduced yield loss, with an approximate 23.8% yield increase relative to non-transgenic counterparts under pathogen infection conditions. This disease resistance is associated with enhanced capacity of the transgenic lines to scavenge reactive oxygen species (ROS), induced by pathogen infection. This finding aligns with the ScALDH21-conferred detoxification function. Transcriptome analyses revealed a significant alteration in expression pattern of those genes that regulate phenylpropanoid and jasmonic acid (JA) pathways. Correspondingly, the accumulation of lignin and defence-related metabolites (e.g., rutin, cyanidin and jasmonates) significantly increased, suggesting that ScALDH21-mediated activation of the phenylpropanoid and JA pathways contributes to enhanced resistance. Analyses of ScALDH21 binding activity using CUT&Tag and EMSA assays showed that it can bind to specific gene promoters within the cotton genome, highlighting that ScALDH21 not only catalyses the detoxification of aldehydes but also gains transcriptional regulatory roles. In summary, we demonstrate that expression of the heterologous ScALDH21 in cotton leads to enhancement of resistance to VW and elucidated the mechanism. Our findings further demonstrate a promising strategy to improve biotic resistance in crops by utilizing unique functional genes from evolutionarily distant species in extreme environments.

PbrIDD2‐PbrAPX14 Module Functions in the Ethylene‐Mediated Ripening and Senescence Process of Pear Fruit

Mon, 27 Apr 2026 06:21:17 -0700

ABSTRACT

Endogenous H₂O₂ participated in the ethylene-dependent ripening and senescence process of horticultural fruit as a secondary messenger; however, the molecular mechanism beneath such a phenomenon has not been fully clarified until recently. By a conjoint analysis of metabolite, enzyme activities, gene expression profiles in AsA-GSH cycle of ‘Kolar’ pear, PbrAPX14 might act as a negative factor in the ethylene-mediated H₂O₂ accumulation. PbrAPX14, located in cytosol, would reduce H₂O₂ in vitro and in vivo, inhibit ethylene production, and thus fruit ripening and senescence. After analysing the expression profiles of the differentially expressed transcription factors (TFs) followed by experimental validation, the nuclear PbrIDD2 could directly bind to the cis-acting element (core motif: TTTGTCG) in PbrAPX14 promoter, activate its expression and thus enhance the H₂O₂-scavenging capacity of fruit/calli, which was associated with the mitigated ethylene evolution and fruit ripening and senescence. Further study explored that the H₂O₂-mediated post-translational S-sulfenylation of Cys⁴⁸ residue in PbrAPX14, which mitigated its function, existed in vitro and in vivo, and was upregulated by ethylene, facilitating endogenous H₂O₂ accumulation. Overall, our results implied that both transcriptional and post-translational regulation of PbrAPX14, which were (in)directly under the control of ethylene, functioned in pear ripening and senescence process via regulating endogenous H₂O₂ level.

Spatiotemporal Metabolome and Single‐Nucleus Transcriptome Integration Illuminates an Auxin Gradient Orchestrated by NtTAC1 Underlying Leaf Angle Regulation in Tobacco

Mon, 27 Apr 2026 02:08:55 -0700

Proposed model of TAC1-mediated leaf angle regulation in tobacco.

ABSTRACT

Plant architecture is key to crop yield, with leaf angle being critical for high-density cultivation. Although TAC1 represents a promising regulator of leaf angle for breeding, its molecular mechanism remains poorly understood, particularly at single-nucleus resolution. Here, we performed single-nucleus RNA sequencing on NtTAC1 knockdown lines exhibiting reduced leaf angle. This analysis generated a transcriptional atlas comprising 20 distinct clusters corresponding to 14 cell types and identified the endodermis as a central regulatory hub. Weighted gene co-expression network analysis and trajectory inference revealed that the auxin transporter NtPIN3 acts as a key downstream effector of NtTAC1. The two genes are co-expressed in endodermal cells and promote their differentiation from meristematic cells. Spatial metabolomics further demonstrated that NtTAC1 suppression elevates auxin levels and alters its spatial distribution, resulting in asymmetric auxin accumulation preferentially in the abaxial region and consequent reduction in leaf angle. Silencing NtPIN3 recapitulated the NtTAC1 disruption phenotype, confirming that the NtTAC1-NtPIN3 axis regulates both auxin asymmetry and cell wall remodelling. Consistently, both knockdown lines exhibited enhanced lignin deposition, linking disrupted auxin flow to secondary wall thickening. Moreover, CRISPR/Cas9-mediated editing of SlTAC1 in tomato suppressed SlPIN3 expression, indicating evolutionary conservation of this module. Collectively, our findings uncover a cell-type-resolved mechanism underlying leaf angle regulation and provide a mechanistic framework for precision engineering of crop architecture adapted to high-density cultivation.

Issue Information

Sat, 25 Apr 2026 21:03:01 -0700

Cover credit:

Cotton is the most indispensable natural fiber crop worldwide. As a premium cultivated cotton species, Gossypium barbadense is globally renowned for its superior fiber quality and serves as an irreplaceable genetic resource for high-quality cotton breeding. Here, we identified the critical regulatory modules controlling fiber elongation and the establishment of superior fiber traits in G. barbadense. These findings offer valuable genetic targets and mechanistic insights for molecular breeding and precise quality improvement of cotton fiber.

WRKY Transcription Factors: Integral Regulators of Defence Responses to Biotic Stress in Crops

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Crops are continually challenged by biotic stresses, including fungal, bacterial and viral pathogens and insect pests, which cause substantial yield and quality losses worldwide. WRKY transcription factors constitute a plant-specific and functionally diverse family that is central to immune regulation. Recent advances in genomic resources and multi-omics approaches have accelerated the identification and functional characterisation of WRKYs in crops. This review summarises the structural features and classification of WRKY genes and their genome-wide distribution across crop species. It also synthesises WRKY-centred regulatory modules that mediate resistance to major classes of biotic stress. In antifungal defence, WRKYs reinforce pattern- and effector-triggered immunity, modulate protein stability and reprogramme secondary metabolism. In antibacterial immunity, they link bacterial perception to cell wall remodelling and hormone and redox signalling. WRKYs also activate PR gene expression, cell wall fortification, RNA interference and programmed cell death to combat oomycete and viral pathogens and insect pests. Overall, WRKYs function as context-dependent transcriptional hubs. They integrate immune signalling with hormonal crosstalk, remodel defence gene networks, and redirect secondary metabolism, thereby shaping resistance outcomes under biotic stress. The review examines WRKY-mediated defence–growth trade-offs and explores opportunities to harness WRKY-centred networks for breeding and engineering broad-spectrum, durable disease and pest resistance. It also highlights how integrating multi-omics with precision genome editing, synthetic biology, gene-drive technologies and artificial intelligence could establish WRKYs as central molecular targets for improving crop resilience and performance.

Bibliometric‐Based Analysis of Global Trends and Collaborative Networks in Plant Genetic Engineering (1994–2024)

Tongxiao Xu, Teng Wang, Cong Zhang, Yuan Cao, Xiaoyun He — Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Agricultural sustainability faces serious challenges from population growth, climate change and ecological degradation. Genetic modification (GM) technology can be regarded as a precise extension of the Green Revolution, aiming to balance yield enhancement with ecological integrity through biotechnology. To systematically examine global trend, this study conducts a bibliometric analysis using worldwide literature data from 1994 to 2024. The findings reveal a dual-core structure of international collaboration, centered on China and the United States. The United States is closely connected with Korea, Japan and the United Kingdom, forming a high-density cluster, while China engages with emerging regions in Southeast Asia and Africa through the Belt and Road Initiative. This initiative is intended to strengthen China's influence and is accompanied by the proliferation of technology in countries less endowed with resources. The technology lifecycle has been evolved through three distinct phases. Initially, the process of Agrobacterium-mediated transformation in tobacco plants was carried out, marking the beginning of transgenic development. This was followed by the implementation of RNA interference (RNAi) technology to silence multiple genes. Finally, a breakthrough happened through the development of CRISPR-Cas9 genome editing technologies. The analyses conducted in this study demonstrate the preponderance of CRISPR in contemporary research, thus suggesting that the industry places a premium on technological refinement. Hence, the future technological trajectory is predicted to focus on germplasm digitization, multi-gene editing, intelligent breeding and synthetic biology. Transgenic technology will serve as a foundational support for achieving sustainable food security in the forthcoming second green revolution.

Harnessing Endogenous Homeobox Genes for Synthetic Apomixis in Hybrid Rice

Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 3324-3326, May 2026.

AtMYB72 as a Biotechnological Tool to Overcome Phenylpropanoid Substrate Limitation and Enhance Coumarin Biosynthesis in Plants

Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 3009-3011, May 2026.

Precise Generation of High‐β‐Carotene Watermelon via Visualised Base Editing

Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 2762-2764, May 2026.

Ralstonia solanacearum Acetyltransferase RipU Hijacks SlJAR1 to Inhibit Jasmonic Acid Signalling and Facilitate Pathogen Infection

Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 2914-2916, May 2026.

Characterisation of Polyamines and Their Biosynthetic Pathways Contributing to Postharvest Anthracnose Resistance in Mango (Mangifera indica L.)

Bei Zhang, Limei Huang, Qingbiao Xie, Hongli Luo, Qiannan Wang, Bang An — Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 2765-2767, May 2026.

Enhancing Metabolic Engineering in Medicinal Plants Through Prime Editing

Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 2858-2860, May 2026.

Two Glutathione S‐Transferase Genes Confer Resistance to Gibberella Ear Rot and Stalk Rot in Maize

Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 3084-3086, May 2026.

Rational Design of Hyoscyamine 6β‐Hydroxylase for the Efficient Production of Scopolamine

Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 3368-3370, May 2026.

High‐Quality Chromosome‐Level Genomes Reveal the Structure and Evolution of the S and Z Self‐Incompatibility Loci in Leymus chinensis

Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 3279-3281, May 2026.

GmRPS5 Promoter‐Driven CRISPR/LbCas12a Efficiently Generates Soybean Sextuple Mutants

Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 3494-3496, May 2026.

MaNAC46 Orchestrates Jasmonic Acid‐Induced Senescence by Coordinating Chlorophyll Catabolism, ROS Homeostasis and Autophagy in Banana

Sat, 25 Apr 2026 21:03:01 -0700

Plant Biotechnology Journal, Volume 24, Issue 5, Page 3048-3050, May 2026.

Rare Natural SNP Activates SHOOT APICAL MERISTEM ENLARGER1 to Increase Branch Number and Silique Number on the Main Inflorescence in Brassica napus

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Brassica napus is the second most important oil crop worldwide. Number of primary branches (Branch number, BN) and silique number on the main inflorescence (SMI) are key yield-related quantitative traits. Here, we cloned a major QTL, qDB.A09, which simultaneously influences BN and SMI. The causal gene, SHOOT APICAL MERISTEM ENLARGER1 (SAME1), encodes a mutator-like transposase-derived transcription factor and is functionally confirmed to positively regulate BN and SMI in B. napus. A rare C-to-A single nucleotide polymorphism (SNP1055), located 1.4 kb downstream of SAME1, is associated with its elevated expression in the boundary region between the organising centre and central zone of the shoot apical meristem (SAM). Functional analysis indicates that high SAME1 expression represses the expression of BnaC06.ARR15 and expands the BnaA09.WUS expression domain, resulting in enlarged SAM size and increased BN and SMI, with BN increased by 3.40 ± 0.45 and SMI increased by 32.67 ± 4.03. In addition, the seed yield per plant is increased by 22.05%. We further demonstrate that qDB.A09 significantly increases BN and SMI in the elite cultivar ZS11, with BN increased by 3.10 ± 0.67 and SMI increased by 27.35 ± 9.12. This study provides a new genetic locus that can be utilised for the genetic improvement of yield-related traits in B. napus.

Pro‐Vitamin A Biofortified Cavendish Banana: Trait Stability in the Field

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Vitamin A deficiency (VAD), a major global health concern, has driven efforts to develop staple crops with enhanced pro-vitamin A (pVA) content. Delivering meaningful nutritional benefits, however, requires technologies that maintain elevated carotenoid levels under field conditions. Previous proof-of-concept work demonstrated that pVA content can be substantially increased in Cavendish bananas through genetic modification, providing a platform for transferring the technology into East African Highland banana (EAHB) cultivars relevant to reducing VAD in Uganda. To evaluate performance under agronomic conditions, we conducted multi-generational field assessments of 27 transgenic Cavendish lines generated from seven constructs enabling constitutive or fruit-preferred expression of three carotenoid biosynthesis genes: ZmPsy1, MtPsy2a and PaCrtI. Constitutive expression was driven by the maize Ubi promoter, while fruit expression was regulated by Exp1 or ACO promoters. Agronomic performance and fruit carotenoid levels were analysed across three generations to explore factors influencing pVA enhancement. All transgenic lines exhibited increased fruit pVA, with the highest accumulation observed in lines constitutively expressing MtPsy2a. Promoter-transgene combinations significantly affected carotenoid accumulation and the stability of the trait in the field. PVA accumulation was the highest in the initial sucker crop and declined in subsequent ratoons, reflecting sensitivity to seasonal conditions. While ACO- and Ubi-driven lines were less affected by seasonal temperature changes, these variations significantly constrained pVA accumulation in wild-type and Exp1-regulated lines. This comprehensive assessment helps elucidate the complex interplay of promoter, isoform, and environmental factors that are essential for the long-term viability of nutritional interventions aimed at combating VAD in the region.

A High Soluble‐Fibre Allele in Wheat Encodes a Defective Cell Wall Peroxidase Responsible for Dimerization of Ferulate Moieties on Arabinoxylan

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Increasing dietary fibre (DF) intake is an important target to improve health. An attractive strategy for this is to increase DF in wheat which is derived principally from the endosperm cell wall polysaccharide arabinoxylan (AX). The water-extractable form of this (WE-AX) accounts for most soluble dietary fibre (SDF), which is believed to confer particular health benefits. A region of chromosome 6B in some wheat varieties confers high SDF and here we show that the cause is an allele encoding a peroxidase family protein with a single residue change (PER1-v) associated with high WE-AX, compared to the more common form (PER1). Both wheat lines carrying this natural PER1-v variant and those with an induced knockout mutation of PER1 showed reduced dimerization of endosperm ferulate consistent with a mechanism of decreased cross-linking in the cell wall that increases WE-AX. Transiently expressed PER1_RFP fusion protein driven by the native promoter in wheat endosperm was shown to localise to cell walls, whereas PER1-v_RFP did not. We therefore propose that PER1-v lacks the capacity to dimerise AX ferulate in vivo due to mis-localisation caused by the missense single-nucleotide polymorphism (SNP) in the PER1-v allele, so that the SNP acts as a perfect marker. This marker can be used to identify current wheat varieties with high WE-AX to be used by processors and by breeders to ensure future varieties have high WE-AX to make healthier wheat-based foods.

A MaERF110‐MaMYB308 Transcriptional Module Negatively Regulates Lignin‐Mediated Defence Against Fusarium Wilt in Banana

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Fusarium wilt of banana (FWB), caused by Fusarium oxysporum f. sp. cubense (Foc), threatens global banana production. Lignin reinforces cell walls against pathogens and lodging, yet its regulatory mechanisms in banana remain elusive. Through genome-wide association study (GWAS) of lignin content across 184 banana accessions, we identified MaERF110 (encoding an AP2/ERF transcription factor) as a key negative regulator. Overexpression of MaERF110 in banana and Arabidopsis significantly reduced lignin deposition, impaired plant structural integrity and enhanced susceptibility to Foc TR4. Integrative RNA-seq, yeast one-hybrid and electrophoretic mobility shift assays revealed that MaERF110 directly binds the MaMYB308 promoter and activates its transcription. MaMYB308 overexpression similarly suppressed lignin biosynthesis genes and compromised disease resistance. Mechanistically, MaERF110-overexpression plants exhibited disrupted reactive oxygen species (ROS) homeostasis, with elevated H₂O₂ and superoxide anion accumulation, reduced antioxidant enzyme activities and increased cell damage upon pathogen infection. We elucidate a MaERF110-MaMYB308 transcriptional module that represses lignin biosynthesis and disables lignin-mediated defence against Foc TR4. This pathway highlights dual roles for lignin in plant architecture and pathogen defence, providing targets for breeding resistant banana cultivars.

H3K27me3‐Mediated Epigenetic Silencing of FgHMG1 Enables Fungal Host Immune Evasion

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Histone H3 lysine 27 trimethylation (H3K27me3) is essential for fungal pathogenicity, yet its contribution to pathogen–host interactions remains incompletely understood. Here, we profiled H3K27me3 dynamics in Fusarium graminearum during infection and identified 132 H3K27me3-marked genes (FgHMGs). Among these, FgHMG1 encodes a secreted glycoside hydrolase family 11 (GH11) protein that functions as a pathogen-associated molecular pattern (PAMP), triggering PAMP-triggered immunity (PTI) in Nicotiana benthamiana through the receptor kinases BAK1 and SOBIR1, independently of its enzymatic activity. FgHMG1 also induces reactive oxygen species (ROS) accumulation and upregulation of defence-related genes in wheat plants. Remarkably, FgHMG1 expression is repressed during host invasion by the histone methyltransferase FgKMT6, a homologue of Enhancer of zeste (E(z)) from Drosophila, via H3K27me3 deposition, enabling immune evasion. Loss of FgKMT6 abolishes H3K27me3 enrichment, derepresses FgHMG1, and enhances host immunity, effects largely rescued in ΔFgKMT6–FgHMG1 double mutants. Notably, foliar application of recombinant FgHMG1 protein reduced Fusarium head blight severity in wheat by 35%–50% in 2-year field trials. These findings reveal that fungal pathogens exploit H3K27me3-mediated silencing of immunogenic PAMP genes to evade host recognition and highlight FgHMG1 as a promising candidate for crop protection.

A Novel Dual‐Target Compound Designed With Potent Herbicidal and Fungicidal Activity Inspired by Conserved Phytoene Synthase Domains

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

The development of dual-target inhibitors represents a cost-effective strategy for integrated pest management. Here, we report the first dual-target inhibitors designed against the evolutionarily conserved domain of phytoene synthase (PSY), a key enzyme in carotenoid biosynthesis. Using comparative genomics, we identified structural conservation between PSY in plants and squalene synthase (erg9) in fungi. Through virtual screening and structure-based optimization of compounds targeting PSY, we identified lead compound 1c, which exhibited potent herbicidal and fungicidal activity. In vitro binding assays confirmed that 1c binds to both PSY and erg9. In plants, 1c treatment reduced chlorophyll content, downregulated photosynthesis-associated genes, and caused substrate accumulation in the carotenoid pathway. In fungi, 1c induced a mycelial morphology identical to erg9 knockout mutants. Molecular dynamics simulations revealed the differential binding conformations of 1c to PSY and erg9, elucidating its mode of action. This work establishes PSY and its homologues as a promising target for the development of novel, broad-spectrum dual-action agrochemicals based on targetome structural similarity.

Autoactive MtDMI1 Reprogrammes Immunity and Development in Tomato via Ethylene Signalling

Haiyue Liu, Ji Xu, Fang Xie — Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

The Common Symbiosis Signalling Pathway (CSSP) underpins interactions between plants and microbes, yet its potential for crop improvement remains underexplored. Here, we investigated the gain-of-function mutant SPD1 (MtDMI1 ^S760N), which constitutively activates the symbiotic signalling pathway in Medicago truncatula, by expressing it in tomato (Solanum lycopersicum cv. Micro-Tom). Heterologous expression of SPD1 constitutively activated ethylene biosynthesis, leading to broad-spectrum resistance against fungal, bacterial, and vascular pathogens. Beyond immunity, SPD1 reprogrammed tomato development, accelerating seed germination, flowering, and fruit ripening, while reducing arbuscular mycorrhizal colonisation and primary root growth. Transcriptome analysis revealed constitutive activation of ethylene biosynthesis and immune marker genes, consistent with increased ethylene emission and amplified ROS and MAPK response to both pathogenic and symbiotic elicitors. Ethylene inhibitor AVG reversed both immune activation and root defects, confirming a central role of ethylene signalling in SPD1-mediated reprogramming. Our findings show that an autoactivate legume symbiotic component can reprogramme defence and development traits in a non-legume via ethylene signalling, highlighting SPD1 as a promising tool for breeding early-maturing and disease-resistance crops.

Mass Spectrometry Imaging Combined With Single‐Cell Transcriptional Profiling Reveals the Multidimensional Spatial Distributions and Biosynthetic Pathways of Medicinal Components in Andrographis paniculata

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

The synthesis and accumulation of active ingredients in medicinal plants are distributed in specific organs, tissues, and cell types, which are important for the exploitation of medicinal plants. However, the fine distribution of active ingredients is difficult to know. Here, the system of mass spectrometry imaging (MSI) integrated with single-cell RNA sequencing was established for the first time in Andrographis paniculata (A. paniculata), a medicinal plant widely utilised in China and Southeast Asia. MSI shows specific distribution of andrographolides in A. paniculata, with higher accumulation in non-veinal leaf regions and outer stem cortex (leaf > stem; outer > inner cortex), as validated by LC-QQQ-MS/MS assays. Leaf scRNA-seq demonstrates that ApCPS2 (the key terpene synthase for andrographolide biosynthesis) exhibits pronounced cell-type-specific expression in photosynthetic mesophyll subclusters, indicating mesophyll cells as the primary site for light-modulated andrographolide production. Interestingly, light may enhance the accumulation of andrographolide biosynthesis, confirming the light sensitivity of metabolism in mesophyll cells. This study explores medicinal components' multidimensional spatial distributions and biosynthetic pathways in A. paniculata via MSI combined with single-cell technology, providing a novel strategy for determining plant metabolites' fine synthesis and distribution.

Haploid Mutation Mapping Identifies a Homoeologous Non‐Reciprocal Translocation Linked to Reduced Fibre and Enhanced Protein in Brassica napus

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

A key challenge for the genetic improvement of canola (Brassica napus), one of the world's most important oilseeds, is the limited natural variation for commercially important traits. The creation of new variation is hindered by the lack of functional knowledge about genes controlling these traits. Ploidy and genomic duplications in canola complicate the effective transfer of functional insights from Arabidopsis. Here, we report a novel functional genomics platform for rapid gene/trait discovery and optimisation. We established a double haploid population of 1240 lines from EMS-mutagenised microspores of the spring-type canola line, NRCDH4079. A platinum-quality reference genome, gene annotations and a gene expression atlas from developing seeds were generated for NRCDH4079. Exome sequencing of the mutagenised population resulted in the development of a ‘TILLED’ database, revealing 1243 premature stop codons across 1222 genes, along with 140 522 moderate-effect or modifier variants impacting 70 626 genes. Phenotypic analysis revealed significant variation in key seed traits, including oil, protein and acid detergent fibre (ADF). Notably, the mutant variant DP125410314 exhibited increased protein and reduced ADF, two important traits for improving the meal composition of canola. Genetic mapping of this variant identified a homoeologous non-reciprocal translocation between A1 and C1 chromosomes associated with reduced ADF content, highlighting the role of structural variations in trait development. This work establishes haploid mutagenesis as a powerful tool for crop improvement, with broader implications for other Brassica species. By enhancing our understanding of seed protein traits, it lays the foundation for canola varieties that meet future nutritional and market demands.

S2‐PepAnalyst: A Web Tool for Predicting Plant Small Signalling Peptides

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Small signalling peptides (SSPs) serve as crucial mediators of cell-to-cell communication in plants, orchestrating diverse physiological processes from development to stress responses. While recent advances in sequencing technologies have improved genome annotation, the identification of novel SSPs remains challenging due to their small size, sequence diversity, and often transient expression patterns. To address this bottleneck, we developed S²-PepAnalyst, a machine learning-powered web tool that integrates plant-specific datasets with advanced computational approaches for SSP prediction and classification. Our platform combines protein language models with geometric-topological feature analysis to capture both sequence and structural characteristics of known SSP families. When validated against experimentally confirmed peptides, S²-PepAnalyst achieved high predictive accuracy (99.5%) while maintaining low false-negative rates. The tool successfully classified peptides into functionally distinct families (e.g., CLE, RALF) and identified non-canonical SSPs that lack traditional signal peptides. Importantly, S²-PepAnalyst demonstrated robust performance across both model plants and agriculturally important species. As a freely available resource (https://www.s2-pepanalyst.uma.es), this tool will empower plant biologists to systematically explore the largely untapped repertoire of plant SSPs, facilitating discoveries in plant cell signalling and potential applications in crop improvement.

The Wheat CRK‐RLCK‐MAPKs Signalling Module Confers High‐Temperature All‐Stage Resistance to Stripe Rust

Yifeng Shi, Yue Xu, Hai Li, Meng Fu, Xu Liu, Yuxiang Li, Xiaoping Hu — Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

As global warming continues, rising temperatures significantly alter the interactions between wheat and the stripe rust pathogen Puccinia striiformis f. sp. tritici (Pst). Utilising high-temperature all-stage (HTAS) resistance to Pst is a novel strategy for breeding climate and disease resilient wheat cultivars. Cysteine-rich receptor-like kinases (CRKs) are involved in massive transduction pathways upon perception of biotic and abiotic stresses in plants. Here, we identify a CRK subfamily gene, TaCRK6, from Xiaoyan 6 (XY6), a wheat cultivar possessing non-race-specific and durable HTAS resistance to stripe rust. The expression of TaCRK6 concurrently responds to both Pst inoculation and the relatively high temperature treatment. Silencing TaCRK6 significantly attenuated HTAS resistance to Pst in XY6. Furthermore, overexpression of TaCRK6 in susceptible wheat cultivar Fielder exhibited a resistant phenotype with reduced Pst sporulation and increased necrosis. TaCRK6 interacts with and primarily phosphorylates the cytoplasmic kinase TaRLCK185 with the threonine residue at position 248. Notably, the MAPK signalling cascades, positioned downstream of TaRLCK185, are proved to participate in activating HTAS resistance in XY6. TaRLCK185 transduces the MAPK cascade signals by interacting with and primarily phosphorylating the serine residue of TaMAPKKK1 at position 132. TaCRK6-mediated phosphorylation of T248 alters the conformation of TaRLCK185, which in turn promotes its interaction with TaMAPKKK1, ultimately leading to activation of the downstream TaMAPKKK1-TaMAPKK9-TaMAPK6 cascade. Moreover, the TaCRK6-TaRLCK185-TaMAPKs module regulates the biosynthesis of salicylic acid (SA). These results indicate a TaCRK6-TaRLCK185-TaMAPKs module that transduces dual stress signals, coupling with the SA pathway initiation to ultimately activate HTAS resistance against Pst in XY6.

Machine Learning‐Driven Construction of High‐Yielding Cucumber Plant Architectures in Greenhouse Environments

Sat, 25 Apr 2026 21:03:01 -0700

Schematic summary of the machine learning-driven analysis for high-yield cucumber architecture. This study employs machine learning methods to analyze key shoot and root traits, building a predictive model for yield. The analysis identifies an optimal plant architecture: a compact and sturdy shoot structure, combined with a narrow yet larger-diameter and shallower root system. This specific architectural synergy is demonstrated to maximize yield in greenhouse environments.

ABSTRACT

In the context of declining arable land, the development of plant architectures that maximise the use of finite resources is crucial for addressing food security. This study collected yield data, along with aboveground and root traits, from 263 cucumber varieties. Machine learning models and scenario simulations were utilised with the goal of identifying a high-yielding cucumber architecture suitable for greenhouse cultivation. Our findings indicate that cucumber yields can be predicted using aboveground and root phenotypes, such as the position of the first female flower node, leaf width, stem diameter, and root angle, with the combination of GBDT and SVM algorithms yielding the most accurate results (R ² = 0.6155, RMSE = 0.2601). Analysis of 157 464 phenotypic combinations revealed antagonistic interactions between robust aboveground structures and fine root systems, and synergistic interactions between slender aboveground parts and broad root systems. Yields were up to 20% higher in phenotypes that combined a compact, robust aboveground structure with a narrow yet larger-diameter and shallower root system, reflecting additive effects rather than synergistic ones. Additionally, this study proposes a reference range for high-yielding phenotypes. Overall, this research provides a theoretical foundation for optimising cucumber plant structures under greenhouse environments by predicting yields and investigating phenotypic interactions through modelling.

Genetic Basis of UV Bullseye Size Variations in Turnip Rape (Brassica rapa subsp. oleifera)

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Floral ultraviolet (UV) patterns are visible to bee pollinators and can affect crop yields by impacting pollinator visitation. However, the mechanisms underlying the intraspecific variations of UV bullseye size remain largely unknown. We analyse the ecological consequences and genetic basis of floral UV bullseye size variation in an important oil crop at high altitudes, Brassica rapa subsp. oleifera (turnip rape). Flowers with larger UV bullseye attract more bees and produce more seeds. The transcription factor BrobZIP16 was newly identified as a key determinant of large UV bullseye, supported by evidence of its high expression and selective sweeps in plants with larger UV bullseye. BrobZIP16 regulates UV bullseye size by interacting with the known regulator BroMYB111 in the flavonoid biosynthetic pathway and accumulating UV-absorbing flavonols. Our results reveal the mechanisms underlying intraspecific UV bullseye size variations, and such ‘cryptic’ large bullseye can be targeted in molecular breeding to increase oilseed production.

The PagDMG6341–PagWD40–PagPOLD4 Module Coordinates Base Excision Repair in ‘84K’ Poplar (Populus alba × P. glandulosa)

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Base excision repair (BER) is a critical pathway for repairing damaged DNA bases in cells; however, the mechanisms of protein recruitment and interaction in this pathway remain largely unexplored in higher plants. In this study, we used ‘84K’ poplar (Populus alba × P. glandulosa) as the experimental system and applied a low concentration of 5-aminouracil (5-AU) to induce DNA base lesions. Through transcriptome analysis and weighted gene co-expression network analysis (WGCNA), we identified two key BER-responsive genes: the DNA glycosylase family gene PagDMG6341 and the DNA polymerase δ subunit PagPOLD4. PagDMG6341 was significantly upregulated during the arrest phase of 5-AU treatment, whereas PagPOLD4 expression peaked during the subsequent release phase. RNA interference (RNAi) lines for each gene resulted in impaired growth and increased susceptibility to 5-AU in ‘84K’ poplar, supporting their functional roles in DNA repair and development. To further investigate their potential interaction network, we performed yeast two-hybrid (Y2H) screening, AlphaFold3-based structural modelling, confirmatory Y2H, bimolecular fluorescence complementation (BiFC) assays, and luciferase complementation imaging (LCI) assays. These experiments demonstrated that a Transducin/WD40-repeat-like scaffold protein (PagWD40) interacts independently with both PagDMG6341 and PagPOLD4. The yeast three-hybrid (Y3H) assay further showed that PagWD40 functions as a molecular scaffold, linking PagDMG6341 and PagPOLD4 to form a functional complex. This study reveals a new mechanism in which PagWD40 functions as a scaffold protein linking a DNA glycosylase with DNA polymerase δ in the plant BER pathway, thereby providing new insights into the organisation of plant DNA damage repair networks.

The MdICE1/MdFAMA‐MdTYDC Transcriptional Module Confers Cold Tolerance by Regulating Dopamine Metabolism in Apple

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Low temperature is a critical abiotic stress that imposes major constraints on the sustainable development of the fruit tree industry. Although exogenous dopamine has been shown to enhance cold tolerance in plants, its molecular mechanisms in apple (Malus domestica) remain poorly understood. In this study, we systematically investigated the role of dopamine in cold stress using exogenous dopamine application, overexpression (OE), and RNA interference (RNAi) of the MdTYDC (a key enzyme in dopamine biosynthesis). Our findings demonstrate that dopamine enhances cold resistance in apple through multiple mechanisms, including reducing reactive oxygen species accumulation, improving photosynthesis and stomatal function, promoting anthocyanin biosynthesis, and upregulating CBF genes. Molecular genetic analyses further revealed that MdICE1, a central transcriptional regulator, directly binds to cis-regulatory elements in the MdTYDC promoter, thereby activating its transcription. Notably, we identified another bHLH transcription factor, MdFAMA, which interacts with MdICE1 and facilitates its binding to the MdTYDC promoter. This interaction amplifies dopamine biosynthesis and strengthens cold resistance. Moreover, exogenous dopamine treatment synergistically induced MdICE1 and MdFAMA expression, forming a positive feedback loop. This feedback mechanism establishes a hierarchical amplification of signalling, further reinforcing tolerance to low temperatures. Collectively, this study elucidates, for the first time, the molecular framework through which the MdICE1/MdFAMA-MdTYDC regulatory module orchestrates dopamine-mediated cold tolerance in apple, providing novel insights into stress adaptation in perennial fruit crops.

Transcription Profiling of Potato Leaves in Response to Heat Stress at Single‐Cell Resolution

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Potato (Solanum tuberosum L.) is a globally important food crop with considerable nutritional and economic value. Heat stress significantly inhibits potato plant growth and tuber development, constraining the sustainable development of the potato industry. Currently, studies on the cellular-level mechanisms underlying heat adaptation in potato remain relatively scarce. In this study, single-nucleus RNA sequencing was employed to construct single-cell transcriptomic maps of potato leaves under normal and heat stress conditions, yielding 77 344 high-quality nuclei and identifying six major cell types. The results indicated that epidermal cells represented the key cell type in heat-stress response, exhibiting the highest number of differentially expressed genes, whereas vascular cells were positioned in the transition zone of the pseudo-time trajectory and may have been involved in cell differentiation processes. By integrating bulk RNA-seq data, a heat stress response co-expression network was constructed, identifying 12 core transcription factors, with StPIF4 appearing repeatedly. Experimental validation confirmed that heat stress strongly induced StPIF4 expression. Functional studies demonstrated that StPIF4 significantly enhanced potato heat tolerance by improving reactive oxygen species scavenging capacity. This study provided cellular-level insights into the mechanisms underlying potato adaptation to heat stress.

OsMT2b Regulates Pollen Development and ROS Homeostasis in a Photoperiod‐Dependent Manner

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Reactive oxygen species (ROS) are signalling molecules that promote programmed cell death in animal and plant systems. However, their role in rice (Oryza sativa L.) anther development is unclear. In this study, we show that lower transcript levels of the metallothionein gene OsMT2b in japonica rice plants obtained by RNA interference (RNAi) resulted in a serious reduction in the seed setting rate. Observations of semi-thin sections of anthers indicated that tapetum degradation initiates early and ends late in OsMT2b-RNAi plants relative to the wild type (WT). Nitroblue tetrazolium staining and measurements of hydrogen peroxide contents showed that ROS contents are higher in OsMT2b-RNAi plants than in WT. Terminal-deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assays showed that abnormal programmed cell death in the tapetum results in sterile microspores. In addition, the OsMT2b-RNAi plants were sensitive to photoperiod; they were sterile under natural long-day conditions but almost fully fertile under natural short-day conditions, indicating that OsMT2b integrates photoperiod information into pollen development. The discovery of this rice material may enrich germplasm resources for two-line hybrid rice breeding, and further research may enable its application in two-line hybrid rice breeding.

Rewiring Steroidal Metabolic Pathways for Diosgenin Production in Solanum nigrum

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Diosgenin is a key starting material for the synthesis of steroidal drugs, such as corticosteroids and sex hormones. While the primary commercial source of diosgenin is the tubers of Dioscorea spp., identifying alternative plant hosts capable of diosgenin biosynthesis could enhance its production. In this study, we present Solanum nigrum, a widely distributed species of the Solanum genus, as a novel platform for diosgenin production. S. nigrum naturally accumulates high concentrations of steroidal glycoalkaloids (SGAs) with a closed F-ring (spirostanol type) in green fruits and steroidal saponins (STSs) with an open F-ring (furostanol type) in leaves. Both classes originate from cholesterol and share the early oxidation steps, followed by specific reactions that redirect distinct metabolic fluxes. In SGAs, the CYP450 enzyme SnGAME4 oxidises C26-OH to an aldehyde, enabling subsequent transamination. In STSs, SnGAME25, a 3β-hydroxysteroid dehydrogenase/isomerase, initiates the reduction reactions at the C5 double bond. Disruption of these two genes shifted the metabolic profiles from the native SGAs and STSs toward furostanol-type proto-diosgenin glycosides. However, these open F-ring structures yield low diosgenin levels during acid hydrolysis. To overcome this limitation, we identified endogenous furostanol glycoside 26-O-β-glucosidases and employed spontaneous fermentation to convert the furostanol structure to the spirostanol structure. Altogether, S. nigrum green fruits yielded diosgenin up to 1% of dry weight. In addition, we engineered S. nigrum to increase fruit number in combination with the SnGAME4 mutation. These results establish S. nigrum as a promising and scalable host for diosgenin production.

A Super‐Pangenome for Cultivated Citrus Reveals Evolutive Features During the Allopatric Phase of Their Reticulate Evolution

Sat, 25 Apr 2026 21:03:01 -0700

Structure of the cultivated citrus super-pangenome.

ABSTRACT

The main genetic diversity observed in cultivated citrus results from a reticulate evolution involving four ancestral taxa whose radiation occurred in allopatry. In such context, GWAS analysis, genome diversity and transcriptomic studies will be significantly enhanced through pangenome approaches. We report the implementation of a super-pangenome for cultivated citrus, established with de novo assemblies of C. medica, C. reticulata and C. micrantha, released for the first time alongside a published chromosome-scale assembly of C. maxima. Repetitive element annotation revealed that half of each genome consisted of transposable elements or DNA-satellites. The new genome assemblies display strong synteny and collinearity, while discrepancies are observed with the C. maxima assembly. Resequencing information from 55 accessions helped to explore the intra- and interspecific diversity of the ancestral taxa and their relationships with horticultural groups. Diagnostic SNPs of the ancestral taxa revealed interspecific introgressions in several representative accessions of C. reticulata, C. maxima and C. medica as well as insights into the origin and phylogenomic structures of horticultural groups. PAV analysis revealed a gene whose absence or presence was specific to one of the ancestral taxa. Diagnostic PAV analysis uncovered a large chloroplastic introgression in C. medica chromosome 4. The analysis of the functional enrichment and species-specific adaptations in the citrus super-pangenome revealed distinct functional specialisations. This highlights the evolutionary paths that have shaped species, contributing to the diversity in the citrus super-pangenome while maintaining a shared foundation of essential biological processes. We established a Genome Hub, offering a platform for continuous genomic research.

Chromosome‐Scale Haplotype Genome Assemblies for the Australian Mango ‘Kensington Pride’ and a Wild Relative, Mangifera laurina, Provide Insights Into Anthracnose‐Resistance and Volatile Compound Biosynthesis Genes

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Mango (Mangifera indica) is one of the most popular fruits cultivated in tropical and subtropical regions of the world. The availability of reference genomes helps to identify the genetic basis of important traits. Here, we report assembled high-quality chromosome-level genomes for the Australian mango cultivar ‘Kensington Pride’ and M. laurina, a wild relative, which shows resistance to anthracnose disease. PacBio HiFi sequencing with higher genome coverage enabled the assembly of both genomes with 100% completeness. Genome sizes of ‘Kensington Pride’ and M. laurina were 367 Mb and 379 Mb, respectively, with all 20 chromosomes in both genomes having telomeres at both ends. K-mer analysis revealed that these genomes are highly heterozygous and significant structural variations were identified between ‘Kensington Pride’, M. laurina, and the recently published genome of the cultivar ‘Irwin’. Functional annotation identified presence/absence variations of key genes involved in carotenoid, anthocyanin, and terpenoid biosynthesis, responsible for fruit colour and flavour in mango. Furthermore, the presence of a SNP in β-1,3-glucanase 2 gene, previously reported to be associated with anthracnose resistance, was analysed. Whole genome duplication analysis confirmed that mangoes have undergone two polyploidization events during their evolution. Analysis revealed a conserved pattern of colinear genes, although many colinear blocks were also identified on non-homologous chromosomes.

Transmembrane Protein GbTMEM209 Inhibits Fibre Elongation via Competitive Interaction With GbHOX3 in Gossypium barbadense

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Sea Island cotton (Gossypium barbadense) produces premium-quality fibres, yet the genetic basis underlying its fibre development remains elusive. Here, we identify two key non-synonymous single nucleotide polymorphisms (SNPs, G/C and G/A) in the gene Gbar_D13G024080, which encodes the TRANSMEMBRANE PROTEIN 209 (TMEM209). These SNPs resulted in amino acid changes (V/L and R/K), and are significantly correlated with the fibre length in Sea Island cotton. CRISPR-Cas9-mediated knockout of GbTMEM209 significantly enhanced fibre length and fibre strength in both G. hirsutum and G. barbadense. Conversely, overexpression of GbTMEM209 in G. hirsutum led to reduced fibre length. Further mechanistic investigation revealed that GbTMEM209 competitively interacts with GbHOX3 to impair its transcriptional activation on cell wall-loosening genes GbEXPA1 and GbRDL1. Moreover, during the elongation stage of the fibres, GbTMEM209 and GbHOX3 exhibit an antagonistic relationship, which jointly regulate the development of cotton fibres. Virus-induced gene silencing (VIGS) of GbHOX3, GbEXPA1, or GbRDL1 consistently resulted in shortened fibres in Sea Island cotton, validating their critical roles in fibre development. Our findings establish GbTMEM209 as a novel negative regulator of fibre elongation and uncover a protein competition-mediated transcriptional control mechanism in cotton fibre morphogenesis. These findings provide valuable genetic targets and conceptual insights for molecular breeding programs aimed at improving cotton fibre quality.

SBP‐Box Transcription Factor JcSPL9 Regulates Both Seed Yield and Oil Content in the Biofuel Plant Jatropha curcas

Mingyong Tang, Xue Bai, Yaoping Xia, Ping Huang, Zeng‐Fu Xu — Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Jatropha curcas is a promising feedstock for biodiesel and bio-jet fuels production; however, its seed yield is constrained by limited inflorescences. SPL9 is a member of the SBP-box gene family that promotes the juvenile-to-adult phase transition. Accumulating evidence demonstrated that the miR156/SPL module plays important roles in regulating diverse plant developmental processes. Here, we reveal that JcSPL9 regulates both seed yield and oil content in Jatropha. JcSPL9 is highly expressed in fruits and upregulated with age in Jatropha. Overexpression of miR156-resistant JcSPL9 (rJcSPL9) significantly increased seed yield and oil content, whereas overexpression of JcmiR156a had the opposite effects. The highest seed yield in rJcSPL9 transgenic plants was 80.76% greater than that in the WT plants, with a concomitant 12.6% increase in seed oil content. Correspondingly, JcmiR156a transgenic plants displayed 51.67% lower seed yield and 8.28% lower seed oil content compared to WT. Additionally, seed oil fatty acid composition was significantly altered in both rJcSPL9 and JcmiR156a transgenic Jatropha and Arabidopsis, as well as in Arabidopsis spl9 mutants. The key oil biosynthesis genes, including JcWRI1, JcDGAT1, JcDGAT2, and JcOLEOSIN, were upregulated in rJcSPL9 transgenic seeds but downregulated in JcmiR156a transformants. This study provides the first evidence that the miR156/SPL9 module regulates lipid accumulation and fatty acid biosynthesis in seeds. These results highlight SPL9 as a promising target for enhancing oil yield and quality in Jatropha and other oilseed crops.

Dissecting the Cell‐Type‐Specific Response to an Emerging Tobamovirus in Tomato Reveals Cultivar‐Dependent Involvement of Brassinosteroid Signalling

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Plant viruses drive widespread crop epidemics, yet the host plant responses across different cell types, particularly how these responses are influenced by cultivars with varying genetic backgrounds, including the presence of resistance (R) genes, remain poorly understood. Using tomato brown rugose fruit virus (ToBRFV) and two tomato cultivars, ‘Jinpeng No. 1’ (JP) and ‘Rutgers’ (RG), with different genetic backgrounds, this study used single-cell RNA sequencing to explore infection dynamics and responses at the cellular level. Results showed that ToBRFV accumulated to different levels in the two cultivars, likely due to differences in their genetic backgrounds, particularly the distinct genotypes of the Tm-2 ² and tm-2 alleles. Following infection, the composition of cell types in tomato leaves also varied between the two cultivars. While the entry or movement of ToBRFV in the JP cultivar was not fully prevented early on, the viral accumulation in certain cell types of this cultivar was restricted. ToBRFV alters signalling pathways based on cell type and cultivars. Pseudotime analysis revealed that, in JP plants, ToBRFV reverses expression of brassinosteroid (BR) positive regulators during mesophyll cell development. Silencing positive BR regulators increased infection in JP plants, while suppressing it in RG plants, linking BR signalling to JP-dependent resistance. Exogenous BR suppressed ToBRFV in JP but enhanced it in RG plants. This study reveals the differential involvement of BR signalling during viral infection in the two cultivars, offering a framework for future studies of plant-virus interactions.

The MdERF17–MdbHLH149 Module Mediates Ethylene‐Induced Starch Degradation Through the Transcriptional Repression of α‐Amylase MdAMY1 in Apple

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

The ripening of climacteric fruits is characterised by a sharp increase in ethylene production, coinciding with the conversion of starch into soluble sugars. However, the regulatory interplay between ethylene and starch degradation in apple remains largely unclear. Here, we report a negative correlation between starch accumulation and ethylene levels during late fruit development. Integrated transcriptomic analysis identified the α-amylase gene MdAMY1 as a key component of the ethylene–starch regulatory pathway. Functional characterisation confirmed that MdAMY1, an ethylene-responsive gene, acts as a positive regulator of starch-to-sugar conversion. Biochemical assays showed that the basic helix–loop–helix (bHLH) transcription factor MdbHLH149 directly represses MdAMY1 transcription. Furthermore, MdERF17—a negative regulator in ethylene signalling—interacts with MdbHLH149 and synergistically enhances this repression. A combination of GUS staining, quantitative enzyme activity assays and VIGS-based transient transformation demonstrated that the MdERF17–MdbHLH149–MdAMY1 module acts downstream of ethylene signalling to control starch degradation. Collectively, these findings establish that ethylene facilitates starch degradation by negatively regulating the MdERF17–MdbHLH149–MdAMY1 repression module.

A Single‐Base Mutation in TaWAK3‐B Reduces Plant Height via Cytoskeleton in Bread Wheat

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Introduction of Reduced height (Rht) genes into modern wheat cultivars has resulted in ‘Green Revolution’ that skyrocketed wheat grain yields worldwide since the 1960s. These ‘Green Revolution’ cultivars show shorter plant height, but higher lodging resistance and harvest index. The identification and exploitation of novel Rht genes are of great significance for the development of high-yielding wheat cultivars. In this study, a semi-dwarf wheat mutant, d14078, with reduced plant height and grain size, was generated by ethyl methanesulfonate (EMS) mutagenesis. Here, through map-based cloning, we cloned the causal gene for the semi-dwarf phenotype of d14078 as TaWAK3-B that encodes a cell wall-associated receptor kinase 3. A single-base mutation occurred in the coding region of TaWAK3-B, resulting in an amino acid mutation from Glu to Lys (E938K) at residue 938, which reduces its stability and the formation of homodimers. The cytoskeletons were changed in both the d14078 and TaWAK3-B knockout mutants, as well as the TaWAK3-B overexpression of transgenic plants. Further investigation revealed that TaWAK3-B directly forms stable protein assembly with TaADF3-A (actin depolymerisation factor), TaKLCR1-A (kinesin light chain-related protein 1), and TaIQD2-D (IQ67-domain protein 2). These interactions and complex formations were significantly attenuated by the TaWAK3-B^E938K mutation. Therefore, our findings clarify TaWAK3-B regulating the microfilament and microtubule formation that elucidate on the regulation of wheat stem development.

Molecular Targeted Suppression of Male Fertility in Amaranthus palmeri S. Watson: Function and Layered Double Hydroxide Nanosheets‐Based Delivery System of ApmiR319

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Amaranthus palmeri is one of the most troublesome invasive agricultural weeds worldwide, exhibiting super invasiveness and high resistance to conventional management strategies. Artificial microRNA-mediated silencing technology, coupled with a nanoparticle-mediated delivery system, represents an attractive approach for fertility control in A. palmeri. In this study, we first characterised the biological function of ApMIR319 via ectopic overexpression in Arabidopsis, identifying it as a crucial candidate molecular target for fertility regulation in A. palmeri. Subsequently, we prepared layered double hydroxide (LDH) nanosheets using the co-precipitation-hydrothermal method. Employing the LDH nanosheets as nanocarriers, we implemented nearly complete encapsulation of the ApmiR319 mimic at a mass ratio of 1:100. The LDH-ApmiR319 mimic complex exhibited stable loading capacity in neutral and alkaline solutions. Furthermore, the LDH-ApmiR319 mimic complex demonstrated robust adhesion to leaf surfaces and enhanced resistance to enzymatic degradation. Spraying treatments with the LDH-ApmiR319 mimic complex significantly elevated ApmiR319 expression levels in male florets, while concurrently down-regulating its target genes (ApTCP4, ApTCP10 and ApMYB33), thereby inhibiting pollen development in A. palmeri. In conclusion, this study successfully established an LDH nanosheet-mediated delivery system of ApmiR319 mimic for male fertility control in A. palmeri. It represents a novel strategy and direction for achieving sustainable management of this weed.

Engineering of 10‐Deacetylbaccatin III‐10‐β‐O‐Acetyltransferase From Taxus Species for Efficient Acetylating Non‐Natural Substrates Into Taxol in Nicotiana benthamiana

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

7-β-xylosyl-10-deacetyltaxol (XDT) is much more abundant than the anticancer drug Taxol in Taxus species and is usually regarded as the by-product of Taxol. It could be enzymatically transformed into 10-deacetyltaxol (DT), and the latter could be further converted into Taxol. The enzyme 10-deacetylbaccatin III-10-β-O-acetyltransferase (DBAT) can acetylate the non-natural substrate DT into Taxol, but the conversion efficiency was extremely low. Herein, we globally redesigned DBAT_cus from Taxus cuspidata to improve its efficiency in DT acetylation through combinatorial protein engineering strategies including virtual saturation mutagenesis, in silico screening, DNA shuffling, and iterative combinatorial mutagenesis. Several more active DBAT mutants against DT were obtained, among which the ICM9-6 exhibited 16.4 times higher activity than DBAT_cus. The transient expression system of Nicotiana benthamiana was then established, and the ICM9-6 was functionally expressed in the system, with yield of 8.2 μg g⁻¹ FW (129.3 μg g⁻¹ DW) Taxol when the system was fed with DT. Specifically, the fungal glycoside hydrolase LXYL-P1-2 that was responsible for converting XDT into DT was also functionally expressed in the system, and upon feeding XDT, the co-expression of LXYL-P1-2 and ICM9-6 yielded 3.6 μg g⁻¹ FW (55.4 μg g⁻¹ DW) Taxol. These results represent the highest reported Taxol productivity in the tobacco system to date and lay a foundation for the construction of the stable transgenic cell lines of tobacco and more efficiently converting DT or XDT into Taxol for the large-scale pharmaceutical manufacturing.

Stress Granule‐Associated ZmCTU2 Confers Thermotolerance in Maize via Coordinated Regulation of Proteostasis and ROS Homeostasis

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

The escalating global temperatures and intensifying heat stress events pose significant threats to maize productivity worldwide. Uncovering key thermotolerance genes and their functional mechanisms is thus critical for developing climate-resilient crops. Here, we report that ZmCTU2, a cytoplasmic tRNA thiolation factor, acts as a central regulator of heat tolerance in maize. Expression of ZmCTU2 correlates positively with kernel-setting under high temperatures. Overexpression of ZmCTU2 confers enhanced thermotolerance at both seedling and adult stages, improving survival and field yield under heat stress, whereas loss-of-function mutants of ZmCTU2 or its partner ZmCTU1 display severe seed developmental defects and lethality. Mechanistically, ZmCTU2 translocates to stress granules under thermal stress, where it recruits ZmCTU1 and ROS-scavenging peroxidases, shielding them from degradation. This dual recruitment facilitates synergistic protective responses: maintenance of tRNA thiolation to ensure translational fidelity, and stabilisation of antioxidative enzymes to bolster redox homeostasis. Our study identifies ZmCTU2 as a scaffold protein within stress granules that coordinates proteostatic and antioxidative pathways under heat stress, providing a valuable genetic resource for engineering thermotolerant maize.

The C2H2‐GGAT Regulatory Module Fine‐Tunes Glutamate Homeostasis to Improve Fruit Flavour and Enhance Disease Resistance in Peach

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Free amino acids (FAAs) play a fundamental role in determining fruit quality and stress adaptation, yet their genetic regulation remains poorly understood. Through an integrated approach combining metabolomic and sensory analyses of 120 peach (Prunus persica) hybrids, we identified glutamate as a key metabolite linking FAA content to umami taste perception. By combining genome-wide association studies (GWAS) with expression quantitative trait locus (eQTL) mapping, we identified PpGGAT1 (glutamate:glyoxylate aminotransferase) and the zinc finger transcription factor PpC2H2-3 as central regulators of glutamate metabolism. Functional characterisation revealed that overexpression of PpGGAT1 led to reduced glutamate levels and diminished umami intensity, whereas PpC2H2-3 transcriptionally suppresses PpGGAT1 to enhance glutamate accumulation. Notably, elevated glutamate levels enhanced resistance to Monilinia fructicola infection, with both genes showing significant expression changes during the progression of brown rot disease. Comparative analysis further indicated that freestone cultivars exhibit superior glutamate accumulation, a trait confirmed across 100 commercial varieties. Our findings reveal a novel regulatory module, PpC2H2-3-PpGGAT1, that coordinately modulates fruit flavour quality and defence responses against pathogens. This study provides mechanistic insights into FAA regulation in fruit crops and identifies actionable molecular targets for the development of varieties with enhanced sensory attributes and disease resistance.

Lily Transcription Factors LlPLATZ1 and LlMYB4 Orchestrate the Homeostasis of Heat Stress Responses via Antagonistic Regulation of LlHSF24

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Heat stress significantly damages crop yield and quality. PLATZ (PLANT A/T-RICH SEQUENCE-AND ZINC-BINDING PROTEIN) transcription factors play pivotal roles in plant growth, development, and environmental stress responses. While the functions of PLATZ members in response to drought and salt stress are well characterised, their roles in heat stress remain largely unexplored. Here, LlPLATZ1, a heat-inducible member of the PLATZ family from lily (Lilium longiflorum), was identified. LlPLATZ1 was rapidly induced by high temperature, and its protein was localised to the nucleus, showing transcriptional repression activity. LlPLATZ1 bound to the promoter of a class B heat stress transcription factor gene, LlHSF24, to inhibit its expression. Stable overexpression of LlPLATZ1 in lily enhanced its thermotolerance, whereas silencing LlPLATZ1 had the opposite effect. Further analysis showed that LlHSF24 directly repressed the expression of heat-protective genes LlHSP22.0 and LlHSP70 to weaken thermotolerance. In addition, LlPLATZ1 interacted with LlMYB4, a later heat-inducible MYB transcription factor that bound to the LlHSF24 promoter to activate its expression. LlMYB4 limited the heat stress response by interacting with LlPLATZ1 to antagonise its DNA-binding ability. In combination, these results indicate that the LlPLATZ1/LlMYB4-LlHSF24 module may play a crucial role in maintaining a balanced heat stress response, enabling plants to adapt to complex environmental changes.

A Highly Conserved SNARE‐Associated Protein Enhances Plant Immunity by Regulating Vesicle Trafficking

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

The plant endomembrane system and vesicle trafficking are central to plant immunity, mediating the targeted delivery and recycling of defence molecules during pathogen attack. Here, we investigated the functional role of soybean Vacuole Membrane Protein 1 (GmVMP1) in mediating resistance against soybean cyst nematode (SCN, Heterodera glycines). GmVMP1 is a SNARE-associated protein whose expression was specifically and transiently upregulated in SCN-resistant soybean roots. Overexpression of GmVMP1 conferred near-complete resistance to SCN. Field-grown transgenic lines showed no developmental penalties and displayed modest gains in seed weight and protein content. GmVMP1 interacted with four key vesicle trafficking proteins, and silencing these interactors compromised GmVMP1-mediated resistance. Live-cell imaging revealed that GmVMP1 enhances endocytic vesicle formation and accelerates internalisation dynamics, pointing to a role in membrane trafficking during defence activation. Together, these results establish GmVMP1 as a novel SCN resistance gene that modulates vesicle trafficking to support early defence, with promising agronomic traits for soybean improvement.

A Specific Sinorhizobium Flagellin Suppresses Legume Nodulation Through Immune Activation

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Bacterial flagellin-activated immunity plays a crucial role in shaping plant-microbe interactions, leading to either parasitism, mutualism, or commensalism. In the legume-rhizobium symbiosis, while it has been hypothesized that rhizobial infection involves avoidance of plant immunity following flagellin perception, direct evidence supporting this regulation remains unclear. Here, we conducted bioinformatic analyses of flagellin variations across the genus Sinorhizobium and identified a specific variant of the flagellin-derived peptide, flg22^Sin-II (clade II flg22 from Sinorhizobium genus), which acts as an immunity elicitor during nodulation. Flg22^Sin-II, but not flg22^Sin-I or flg22^Sin-III, activates immune responses, including reactive oxygen species production, MPK phosphorylation, and immunity-related gene expression in soybean, with Tyr-7 being critical for the immune activation. Three different Sinorhizobium mutants knocking out the flagellin that produces flg22^Sin-II enhanced nodulation across three diverse legume species, highlighting how beneficial microbes modulate host immunity to optimize symbiotic interactions. Soybean gmfls2a gmfls2b double mutant lacking both flagellin receptors, GmFLS2a and GmFLS2b, exhibited an increased nodule number following S. fredii HH103 inoculation and showed reduced expression of immune-related genes in nodules. Rather than complete immune evasion, the retention of an immune-activating flagellin epitope by Sinorhizobium likely represents a sophisticated coevolutionary strategy to actively modulate host responses, ensuring symbiotic homeostasis and preventing detrimental over-colonisation.

A Fusarium sacchari Glycoside Hydrolase 12 Protein FsEG1 Is a Major Virulence Factor During Sugarcane Infection and Confers Resistance to Pokkah Boeng Disease via the HIGS Strategy

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Pokkah Boeng disease (PBD), caused by Fusarium sacchari, has severely impacted the yield and quality of sugarcane, resulting in significant economic losses. However, the molecular interaction mechanisms between F. sacchari and sugarcane remain poorly understood. In this study, we identified the GH12 family protein FsEG1, secreted by F. sacchari, as a critical virulence factor. Further analysis demonstrates that the hydrolase activity of FsEG1 is essential for the full virulence of F. sacchari. The enhanced immune responses and cell death induced by FsEG1 in N. benthamiana depend on the recognition of oligosaccharide elicitors derived from the degradation of host cell walls by FsEG1, which are detected by membrane-localised receptors NbWAKs and NbCERK1, and this process also necessitates RAR1 and MAP3Kα to facilitate intracellular signal transduction. Consequently, FsEG1 activates DTI (DAMP-triggered immunity) rather than the conventional PTI. The stable transgenic sugarcane plants carrying the FsEG1 RNAi hairpin construct displayed high levels of resistance to F. sacchari and decreased FsEG1 expression, production of specific FsEG1 siRNA in transgenic HIGS sugarcane plants was confirmed by stem-loop qRT-PCR; at the same time, the stable transgenic sugarcane plants with ectopic expression of FsEG1 also showed enhanced PBD resistance with activated expression of defence-related genes. Overall, these findings establish a foundational basis for investigating the molecular mechanisms that govern the interactions between F. sacchari and sugarcane and offering valuable insights into enhancing sugarcane's resistance to PBD.

OsWRKY53‐OsGT1 Module Regulates Rice Tiller Development and Is Involved in Fine‐Tuning Strigolactone Signaling

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Plant architecture, including plant height, tiller number, and leaf angle, is a critical determinant of rice yield. However, few genes have been identified that simultaneously regulate these traits and hold breeding value. We have previously shown that OsWRKY53 regulates the plant height and leaf angle via BR signalling. Here, we establish OsWRKY53 as a novel negative regulator of tillering in rice. The oswrky53 mutant exhibits a semi-dwarf stature coupled with increased tiller number, representing a promising agronomic combination. Genetic and molecular analyses reveal that OsWRKY53 acts as a direct transcriptional activator of OsTB1, thereby suppressing tiller formation. In addition, we found OsWRKY53 physically interacts with OsGT1, and their cooperative action synergistically enhances OsTB1 expression and suppresses tiller number. Intriguingly, the oswrky53 mutant exhibits reduced sensitivity to Strigolactone (SL) and increased SL contents. We further demonstrate that SL promotes degradation of OsWRKY53, and D53 interacts with and stabilises the OsWRKY53. Simultaneously, OsWRKY53 negatively regulates SL biosynthesis, enabling OsWRKY53 to function as a fine-tuning regulator in the SL signalling pathway. Furthermore, OsGT1 exhibits subspecies-specific regulation, with indica accessions carrying the OsGT1 ^581T allele showing significantly enhanced tillering capacity compared to japonica varieties. These findings collectively reveal the mechanism by which OsWRKY53 regulates the formation of tillers in rice, providing new genetic targets for semi-dwarf and high-tillering rice breeding.

Serial Spatial Transcriptomes Reveal Regulatory Transitions in Maize Leaf Development

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Plant leaves originate from the shoot apical meristem (SAM) and undergo a developmental process of highly coordinated gene expression regulation. To date, only a few key regulators have been identified and characterised, so the gene expression cascades responsible for leaf cell specification and differentiation from SAM remain largely elusive. Here, we optimised a spatial transcriptomics protocol using the 10× Genomics Visium system and developed computational pipelines to reconstruct three-dimensional gene expression profiles of the SAM and sequentially developing leaves in maize seedlings. These enabled positional indexing of cells sampled from consecutive developmental stages, revealing dynamic transitions from undifferentiated stem cells in the SAM to functionally differentiated leaf structures. Through spatial–temporal transcriptome analysis, we identified distinct transcriptional programs and key regulatory genes involved in meristem maintenance, leaf primordia initiation, vascular tissue differentiation, and cellular heterogeneity. This approach outperforms the single-cell transcriptome profiling, which lacks temporal and spatial contexts. Our optimised experimental pipeline, which goes from section preparation to data processing, enables the spatial resolution and 3-dimensional mapping of gene expression profiles. The established pipeline is readily applicable to delineating molecular events underlying developmental transitions, cell type specifications, and differentiation in plants.

Tomato Spotted Wilt Virus Reprogrammes Host Glycolysis to Facilitate Proliferation by a Phase‐Separated Co‐Aggregate of Nucleocapsid Protein and Phosphoglycerate Kinase

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

Efficient viral proliferation within the host is a critical step in pathogenicity and requires adenosine triphosphate (ATP). The replication, movement and immune evasion of many plant viruses within their hosts are associated with phase separation (PS)-derived aggregates formed by viral components. However, the host factors that drive the formation of these condensates remain largely unknown. This study provides evidence that the nucleocapsid protein (N) of tomato spotted wilt virus (TSWV) recruits the host factor phosphoglycerate kinase (NbPGK) from Nicotiana benthamiana to form phase-separated condensates. This remodels the host glycolytic pathway to generate ATP, supplying energy for viral replication via ribonucleoprotein complexes and acting as a promoter to regulate the PS network, thereby facilitating condensate formation. Notably, we have developed a small-molecule PS modulator, F10. By combining drug affinity-responsive target stability, molecular docking, microscale thermophoresis and bio-layer interferometry techniques allowed F10, we confirmed binding to sites Arg94, Lys192 and Gly228 on TSWV N, residues critical for maintaining NbPGK recruitment. F10 interacts with N, liberating the hijacked host factor NbPGK, and exhibits potent antiviral activity, outperforming the commercial virucide Ningnanmycin. This study elucidates the molecular machinery underlying viral exploitation of host cellular metabolism and identifies a lead compound that is amenable to managing TSWV by targeting this process.

Tandem MADS‐Box Genes FUL2 and MADS1 Form a Regulatory Module to Repress Serotonin Biosynthesis via Direct ASMT5 Activation in Tomato Fruit

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

The regulation of serotonin metabolism during fruit development and ripening remains poorly understood, despite its potential roles in plant defence and human nutrition. Here, we demonstrated that the MADS-box transcription factor FUL2 acts as a key repressor of serotonin accumulation in tomato by forming a functional module with MADS1. CRISPR-Cas9-generated ful2-cr mutants exhibited delayed ripening, reduced fruit size and a striking 10-fold increase in serotonin levels, suggesting a previously unrecognised link between FUL2 and secondary metabolism. Immunoprecipitation-mass spectrometry (IP-MS) revealed that FUL2 physically interacts with MADS1, and genetic analyses showed that mads1-cr mutants phenocopied both the developmental and serotonin hyperaccumulation phenotypes of ful2-cr mutants. Furthermore, ChIP-seq and transcriptomic profiling demonstrated that the FUL2-MADS1 complex directly binds CArG-box motifs in the promoter of ASMT5 (a key enzyme in serotonin-to-melatonin conversion), activating its expression while repressing TDC1 (tryptophan decarboxylase). Electrophoretic mobility shift assays (EMSA) and dual-luciferase reporter assays confirmed their cooperative DNA binding and synergistic transcriptional regulation. Our work establishes a MADS-box transcriptional module that gates serotonin flux by coordinately regulating biosynthetic and metabolic genes. These findings provided a framework for engineering serotonin content in crops and deepen understanding of how developmental transcription factors govern specialised metabolism during ripening.

The miR319/bHLH094 Module Regulates Creeping Bentgrass Thermotolerance by Modulating Auxin Biosynthesis and Signalling Pathway

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

MicroRNA319 (miR319) has been demonstrated to regulate plant development and responses to stress such as drought and salt. However, its role in thermotolerance, particularly in cool season grasses, remains unclear. Here we report that miR319 plays a negative role in heat tolerance of creeping bentgrass (Agrostis stolonifera). A basic helix–loop–helix (bHLH) transcription factor, AsbHLH094 was identified as the target gene of miR319, and its expression was significantly downregulated in the miR319-overexpressing (OE319) transgenic creeping bentgrass lines. Functional characterisation revealed that overexpression of AsbHLH094 enhanced heat tolerance of the transgenic tobacco plants. Furthermore, protein–protein interaction assays confirmed that AsbHLH094 physically interacts with AsIAA1, an Aux/IAA protein involved in auxin signalling. Transcriptomic analysis showed that auxin biosynthesis genes such as TARs, YUCCAs, along with auxin-response genes including Auxin/IAAs and ARFs were downregulated in the OE319 transgenic creeping bentgrass plants, leading to reduced auxin accumulation, while elevated auxin levels and induced changes in auxin biosynthesis- and response-related genes were observed in the AsbHLH094 overexpression tobacco. Endogenous indole-3-acetic acid (IAA) levels in creeping bentgrass were significantly increased under high-temperature conditions, and exogenous application of IAA at appropriate concentrations improved heat tolerance in creeping bentgrass. Together, our findings reveal a previously uncharacterized miR319-AsbHLH094 regulatory module that modulates auxin biosynthesis and signalling, thereby contributing to heat stress responses in creeping bentgrass.

Engineering Marker‐Free Lettuce Chloroplast Genome to Express Functional Glucagon‐Like Peptide‐1 Receptor Agonists Exenatide and Lixisenatide

Rahul Singh, Henry Daniell — Sat, 25 Apr 2026 21:03:01 -0700

Engineering of marker-free lettuce chloroplast genome to express CTB-Exenatide and CTB-Lixisenatide for oral delivery. Upper panel: Chemically synthesised exenatide or lixisenatide require expensive production, purification, refrigeration and invasive delivery methods. Lower panel: Exenatide or lixisenatide fusion with CTB expression in marker-free lettuce facilitates oral delivery and reduces cost by elimination of fermentation or chemical synthesis, purification and cold chain. CTB: Cholera toxin subunit-B—transmucosal carrier tag.

ABSTRACT

Diabetes Mellitus is an epidemic affecting > 500 million, claiming 6–7 million lives annually. Chemically synthesised Glucagon-like peptide-1 receptor agonists (GLP-1RAs) containing artificial amino acids reduce haemoglobin A1c and obesity but are not yet affordable and require invasive injections. High dosage requirement and gastrointestinal complications are among the current limitations of oral GLP-1RAs. Therefore, we expressed codon optimised Exenatide and Lixisenatide fused with Cholera-toxin B-subunit (CTB) in lettuce chloroplasts to facilitate their oral delivery, increase affordability, and patient compliance. Site-specific integration of transgene expression cassettes into the chloroplast genome and removal of the selectable marker gene from marker-free lettuce transplastomic lines were confirmed using three sets of PCR primers. Homoplasmy in transplastomic lines was confirmed in Southern blots by the absence of untransformed genomes. CTB-Exenatide and CTB-Lixisenatide expression levels were 1.94 and 3.64 mg/g plant powder in T0 generation and increased ~31 and ~48%, respectively in marker-removed T1 lines. Maternal inheritance of transgenes was confirmed by lack of segregation when seedlings were germinated in the selection medium before removal of the antibiotic resistance gene (aadA). Monosialotetrahexosylganglioside (GM1) ELISA confirmed pentameric assembly efficiency of both CTB-fusion proteins similar to commercial CTB standards. GLP-1 receptor binding confirmed functionality of CTB-Exenatide/CTB-Lixisenatide with statistical significance (***p < 0.001 by t-test) and post-translational amidation in chloroplasts. Expression of functional CTB-Exenatide and CTB-Lixisenatide in an edible marker-free system for the first time and much lower dosage requirement for functionality than recently developed synthetic GLP-1RAs paves the way for clinical studies to advance oral delivery of these affordable biologics.

Salvia miltiorrhiza‐Derived Vesicle‐Like Nanoparticles Functionalised Hydrogel With Excellent Ability of Oxidative Stress Modulation and Anti‐Cardiomyocyte Apoptosis for Sepsis‐Induced Myocardial Injury

Sat, 25 Apr 2026 21:03:01 -0700

ABSTRACT

In the process of myocardial cell structural and functional damage caused by various factors, current therapeutic strategies primarily focus on restoring myocardial blood supply, often neglecting the inherent complex microenvironment triggered by elevated reactive oxygen species (ROS) levels during myocardial injury. Regulating mitochondrial function and inhibiting excessive ROS production to alleviate myocardial apoptosis are therefore critical for myocardial injury repair. Plant-derived vesicle-like nanoparticles have shown broad applications in multiple fields and possess potential value. In this context, the present study introduces Salvia miltiorrhiza-derived nanoparticles (SDVLNs) to counteract ROS effects after myocardial infarction. We performed in vitro experiments to analyse the effects of SDVLNs on cardiomyocyte proliferation, migration, oxidative stress, and mitochondrial function. Meanwhile, a novel concept of “natural plant-derived vesicle-like nanoparticles-gel” was proposed to address the stringent storage requirements of SDVLNs. We loaded SDVLNs into a thermo-sensitive hydrogel to prepare SDVLNs@hydrogel (SDVLNHs), and further conducted in vivo experiments to evaluate the therapeutic effects of locally administered SDVLNHs in lipopolysaccharide (LPS)-induced myocardial injury mice, with a focus on cardiac function and pathological changes in the heart. It was found that SDVLNs promoted cardiomyocyte proliferation and migration, alleviated oxidative stress, regulated mitochondrial function, and inhibited myocardial apoptosis. The developed SDVLNHs addressed the stringent storage requirements of SDVLNs, and local administration of SDVLNHs significantly improved cardiac function and reduced pathological damage in LPS-induced myocardial injury mice. Collectively, these findings highlight the potential of SDVLNs in myocardial injury repair and their applicability as a promising solution for myocardial injury in clinical settings.

DcH3.3 and DcNAC1 Regulate the Expression of UGT73A93 Involved in the Changes in Flower Colour and Fungal Resistance in Carnation

Sat, 25 Apr 2026 05:50:52 -0700

ABSTRACT

Carnation (Dianthus caryophyllus) contains abundant flavonoid glycosides (FGs), which are important natural functional and colour components. However, there are few reports on the modification of UDP-glycosyltransferases (UGTs) in relation to flavonoids in carnation. In this study, we cloned and characterised a flavonoid 3′-O-glucosyltransferase (UGT73A93) in carnation in vitro. Overexpression of UGT73A93 in carnation and tobacco increased flavonoid glycoside accumulation, particularly kaempferol glycosides, while decreasing anthocyanin content and lightening flower colour. UGT73A93 also enhanced fungal resistance, antioxidant capacity, anti-amylase and anti-pancreatic lipase activities. Yeast one-hybrid and dual-luciferase assays revealed that the UGT73A93 promoter interacted with DcH3.3 and DcNAC1, key regulatory proteins involved in flavonoid biosynthesis. We predicted the interaction between DcLON2 and DcNAC1 using AlphaFold 3 and confirmed this hypothesis through yeast two-hybrid assay and bimolecular fluorescence complementation assays. These findings suggest an epigenetic-transcriptional cascade (DcH3.3–DcNAC1–UGT73A93) wherein DcH3.3 opens chromatin for DcNAC1-mediated UGT73A93 activation, while DcLON2 potentially degrades DcNAC1 to form a feedback loop. These results provide new insights into flavonoid 3′-O-glucosyltransferase and may contribute to future strategies aimed at improving the benefits of flavonoid biosynthesis for both plants and humans. It also demonstrates that AI can be applied in the field of plant biosynthesis, accelerating the process of plant breeding.

Engineering of Amygdalin Biosynthesis in Rice Endosperm for Pharmaceutical Production and Sitophilus oryzae Resistance

Tue, 21 Apr 2026 06:47:10 -0700

Plant Biotechnology Journal, EarlyView.

Mapping and Functional Characterization of Homologous Genes AhSUCA06 and AhSUCA16 Underlying Sucrose, Oil and Protein Contents in Peanut (Arachis hypogaea L.)

Sat, 18 Apr 2026 00:25:31 -0700

ABSTRACT

Cultivated peanut (Arachis hypogaea L.) is an important oilseed and cash crop, and seed sucrose content (SSC), seed oil content (SOC) and seed protein content (SPC) are key determinants of seed flavour, texture, and overall quality. Identifying quantitative trait loci (QTLs) and candidate genes associated with SSC, SOC and SPC is therefore of considerable importance for peanut genetics and breeding. In this study, two recombinant inbred line (RIL) populations derived from reciprocal crosses between the lines Jihuatian1 (JHT1) and PI478819 (PI) were used to detect major QTLs for SSC, SOC and SPC through bulked segregant analysis combined with whole-genome sequencing (BSA-seq). Multiple lines of evidence supported the homologous gene pair AhSUCA06 and AhSUCA16 as candidate genes underlying the epistatic QTLs qA06.1 and qA16.1, which exhibited major and stable effects across multiple phenotypic evaluations. Furthermore, the function of AhSUCA06 was validated through CRISPR/Cas9-mediated genetic transformation. Subcellular localization assays using GFP fusion proteins, together with dual-luciferase reporter assays, demonstrated that AhSUCA06 and AhSUCA16—both containing a DUF7950 domain of previously unknown function—localize to the nucleus and act as transcriptional repressors. In addition, DAP-seq analysis suggested that these genes may regulate pathways related to glycolysis and gluconeogenesis. Overall, this study provides new insights into the molecular mechanisms underlying the regulation of SSC, SOC and SPC in peanut and offers valuable information to support the genetic improvement of seed quality traits in peanut breeding programs.

Transcriptional Regulation of the Novel Theacrine Synthase Gene CsTcS2 by the CsTINY–CsWRKY33 Module Underpins Theacrine Biosynthesis in Camellia sinensis

Wed, 15 Apr 2026 06:20:38 -0700

ABSTRACT

Theacrine (1,3,7,9-tetramethyluric acid) is a purine alkaloid detected in multiple wild and specialised tea germplasms (Camellia sinensis) from South China, including Kucha. However, the molecular mechanisms governing its biosynthesis remain poorly understood. Here, we identify CsTcS2 as a novel theacrine synthase in tea plant. Functional assays involving heterologous expression in Nicotiana benthamiana, antisense oligonucleotide-mediated gene silencing, transient overexpression in tea plants and co-expression with caffeine dehydrogenase (CsCDH) confirm its catalytic role in converting caffeine to theacrine. Transcription factors CsTINY and CsWRKY33 directly bind the CsTcS2 promoter and activate its transcription, as demonstrated by yeast one-hybrid, dual-luciferase reporter and electrophoretic mobility shift assays. Further molecular docking, yeast two-hybrid, bimolecular fluorescence complementation, luciferase complementation, co-immunoprecipitation and antisense inhibition experiments reveal a synergistic interaction between CsTINY and CsWRKY33 that regulates CsTcS2 expression and thus controls theacrine biosynthesis. Together, our findings unravel the transcriptional regulatory network underlying theacrine biosynthesis and provide a molecular foundation for breeding tea cultivars with elevated theacrine levels for health-promoting applications.

Unfolding Plant Defence: Endoplasmic Reticulum Stress Signalling at the Plant‐Pathogen Interface

Sat, 11 Apr 2026 03:59:18 -0700

ABSTRACT

The endoplasmic reticulum (ER) stress response, a conserved proteostasis network, has emerged as a central hub that reprograms plant immunity during pathogen attack. This review synthesises how plants harness ER-stress signalling to mount multilayered defences and how pathogens have evolved counterstrategies to subvert these pathways. We delineate the molecular integration of the unfolded protein response (UPR) with canonical immune layers including pattern-triggered immunity (PTI), effector-triggered immunity (ETI) and systemic defences, highlighting salicylic acid (SA) and jasmonic acid (JA) as rheostats that fine-tune ER stress-immune crosstalk. Functionally, the UPR bolsters immunity by coordinating protein folding and secretion, reprogramming transcription and translation, activating ER-dependent programmed cell death (ER-PCD), and orchestrating ER-associated degradation (ERAD) and selective autophagy. Pathogens such as bacteria, oomycetes and viruses in turn deploy virulence factors that target UPR sensors and transcription factors, thereby attenuating ER-driven immunity. We propose a conceptual framework in which the outcome of UPR activation—resistance versus susceptibility—is determined by pathogen lifestyle, ER stress dynamics, subcellular compartmentalisation and pathogen effector intervention. We also consider biotechnological contexts in which strong transgene expression can itself provoke the UPR, and outline diagnostic experimental strategies to distinguish UPR-mediated effects from intended transgene functions. By integrating molecular mechanisms with pathogen counterstrategies, this review underscores the dynamic interplay between ER stress and immune signalling in plants and highlights opportunities to enhance crop resilience under global climate challenges.

Rice EMF3 Alleles Adjust Flower Opening Time to Enhance the Seed Setting Rate Under High Temperature Stress

Thu, 09 Apr 2026 05:29:47 -0700

ABSTRACT

To safeguard global food security against rapid population growth and a warming world, the effective genetic improvement of cereals is imperative. Flower opening time (FOT) critically affects the seed setting rate. In this study, we identified a gene, EARLY-MORNING FLOWERING 3 (EMF3), in which single-nucleotide substitutions strongly modulate FOT in rice in a semi-dominant manner, resulting in wide variation in FOT from earlier to later FOT than the wild-type. EMF3 knock-out mutants showed significantly reduced FOT synchrony and disrupted anther dehiscence, leading to fertilisation failure. EMF3 encodes a plasma membrane-localised polypeptide of 723 amino acids with an armadillo repeat fold and four transmembrane segments. Furthermore, EMF3 is specifically expressed in the anthers starting from nighttime on the day of flowering, with substantial impacts on the transcriptomes of both anther and lodicule, which suggested an exclusive role of EMF3 in flowering events. Modifying EMF3 alleles of O. sativa enabled the adjustment of FOT among Oryza species and subspecies, potentially facilitating cross-fertilisation by overcoming one of the major challenges of inter-specific hybridisation to exploit heterosis. Introducing the EMF3 alleles with the earlier FOT into popular rice cultivars resulted in flowering at an earlier time of day when the temperature was cooler, efficiently increasing seed setting rate under heat stress. This discovery unveils the novel mechanism of anther control of flower opening time through the EMF3 gene, while also enabling the use of EMF3 alleles in breeding strategies for efficient fertilisation for increasing hybrid rice seed production and mitigating future heat-stress damage at flowering.

Spatial Regulation of Silicon Accumulation in Peduncle Confers Sheathed Spike in Barley

Wed, 08 Apr 2026 04:36:23 -0700

ABSTRACT

Peduncle, the uppermost internode in cereals, connects the stem to the inflorescence and is critical for the transport of water, nutrients and photosynthetic assimilates. While peduncle length associates with plant height and its elongation is primarily regulated by phytohormones, we report a previously unrecognized mechanism involving the spatial distribution of silicon (Si). We identified a barley mutant, sheathed spike 2 (ss2), characterized by a specifically shortened peduncle that traps the spike within the flag leaf sheath. Positional cloning and analysis of allelic mutants revealed that the wild-type SS2 gene encodes a putative silicon efflux transporter. SS2 is expressed throughout the lifecycle, with higher transcriptional levels in the rachis and stem internodes, and its encoded protein localizes to the plasma membrane. We demonstrate that SS2 is required for polarized Si partitioning. Unlike wild-type plants, which ultimately deposit Si in spikes, the ss2 mutant exhibits an 8-fold increase in Si accumulation in the peduncle and a significant increase in the flag leaf. Hydroponic experiments without Si supply restored normal peduncle elongation in the ss2 mutant, demonstrating that local Si hyper-accumulation directly inhibits elongation. The conserved role of SS2 was supported by diversity analysis across barley and common wheat, as well as by the similar sheathed spike phenotype in tetraploid wheat lines carrying non-functional SS2 homologues. Collectively, our findings uncover an evolutionarily conserved, silicon-dependent mechanism that regulates peduncle elongation and spike emergence in Triticeae crops like barley and wheat.

First Tetraploa Genome and Multi‐Omics Analysis Reveal Key Plant‐Microbe‐Soil Interactions for Salt Tolerance and Yield Improvement of Wheat

Fri, 03 Apr 2026 21:59:23 -0700

ABSTRACT

Salinity is a major threat to global agricultural productivity of staple crops such as wheat. Although microbial-based solutions hold promise for alleviating salinity stress, practical implementation is hindered by insufficient mechanistic characterization of bioinoculants and their interactions with plants. Here, we assembled the first complete reference genome of a halotolerant strain within the genus Tetraploa—the endophytic fungus Tetraploa sp. E00680. This novel genomic resource serves as a foundation for exploring previously uncharacterised salt tolerance mechanisms in this potential fungal inoculant. Our research demonstrates that E00680 enhances wheat yield under both controlled and field saline conditions. We found that E00680 systematically modulates the plant-microbe-soil interactions by optimizing rhizosphere microbial communities, increasing nutrient bioavailability, and triggering coordinated transcriptional and metabolic reprogramming in wheat. Notably, E00680 expands tryptophan metabolism to synergistically boost auxin biosynthesis in wheat by supplying precursors and activating relevant metabolic pathways. This cross-kingdom metabolic coupling facilitates better growth and salt tolerance in wheat plants. Our findings offer multi-omics and rhizosphere-level insights that can guide the development of microbial inoculants to enhance climate-resilient and sustainable crop production.

Regulatory Mechanism of CsMYB1‐CsMYB82/CsbHLH48‑CsCAD4 Model for Resistance Against Colletotrichum gloeosporioides in Camellia sinensis

Fri, 03 Apr 2026 21:29:58 -0700

ABSTRACT

Anthracnose caused by Colletotrichum gloeosporioides is a major threat to tea cultivation; however, the molecular mechanism underlying different resistance among tea cultivars remains unclear. We identified distinct expression patterns of CsMYB82 between anthracnose-resistant and susceptible varieties after infection with anthracnose from previous RNA-seq data. We further investigated the role of CsMYB82 within a lignin-associated regulatory network during anthracnose responses. We found that CsMYB1 negatively regulates CsMYB82 expression by Y1H screen. Additionally, we identified the interaction between CsMYB82 and CsbHLH48 both in vitro and in vivo. DNA-affinity purification sequencing (DAP-seq) revealed that CsMYB82 directly binds to the promoter of CsCAD4, and this binding activity is enhanced in the presence of CsbHLH48. Functional analyses indicated that overexpression of CsMYB82 or CsCAD4 in tobacco and tea leaves was associated with increased susceptibility to anthracnose, whereas transient silencing of CsMYB82 or CsCAD4 via virus-induced gene silencing (VIGS) in tea leaves resulted in reduced disease symptoms accompanied by elevated lignin accumulation. The functional analysis of CsMYB1 showed the opposite phenotype. Collectively, these results suggest that CsMYB82 participates in a transcriptional regulatory module involving CsMYB1, CsbHLH48, and CsCAD4, which modulates lignin biosynthesis and influences anthracnose responses in tea plants. This study provides mechanistic insights into the transcriptional regulation of lignin-associated defence responses and contributes to a better understanding of anthracnose resistance in tea.

Establishment of an Agrobacterium‐mediated CRISPR/Cas9 Genome Editing System for Kenaf (Hibiscus cannabinus)

Fri, 03 Apr 2026 21:08:53 -0700

Plant Biotechnology Journal, EarlyView.

Precise Creation of Elite Multilocular Germplasm Using a CBE NG System in Brassica napus

Fri, 03 Apr 2026 04:41:30 -0700

Plant Biotechnology Journal, EarlyView.

Redundant Glycerol‐3‐Phosphate Acyltransferases Regulate Thermo‐Sensitive Genic Male Sterility in Rice

Wed, 01 Apr 2026 06:31:17 -0700

ABSTRACT

Thermo-sensitive genic male sterility (TGMS) lines play a pivotal role in two-line hybrid rice breeding. However, the availability of elite TGMS germplasm remains limited, and the molecular mechanisms underlying fertility transition of TGMS lines are still poorly understood. Here, we identified a novel TGMS line, Osgpat6.1, which exhibits temperature-dependent fertility transition, with male sterility under high-temperature (HT) and restored fertility under low-temperature (LT). Cytological observations revealed that the TGMS line exhibits disrupted programmed cell death (PCD) of the tapetum under HT conditions. This disruption leads to delayed tapetum degradation and defective pollen exine formation. Map-based cloning identified a premature termination mutation in glycerol-3-phosphate acyltransferase 6.1 (OsGPAT6.1), which is highly expressed in anthers and essential for lipid biosynthesis. Lipidomic profiling revealed that disruption of OsGPAT6.1 perturbed lipid metabolism during pollen development. Genetic studies further revealed that male sterility in Osgpat6.1 mutant was restored through functional redundancy with its homologues OsGPAT6.2 and OsGPAT6.3 under LT. Overexpression of OsGPAT6.2 or OsGPAT6.3 partially restored the fertility of Osgpat6.1 mutant under HT. However, simultaneous disruption of all three homologues abolished fertility restoration even under LT. Notably, introgression of the Osgpat6.1 allele into diverse rice cultivars produced stable TGMS lines without compromising hybrid vigor. Collectively, these findings demonstrate that dysfunction of GPAT confers TGMS in rice by disrupting glycerolipid metabolism and provides TGMS germplasm to facilitate two-line hybrid rice breeding.

Field Trials and Baking Studies of Ultra‐Low Asparagine, Genome Edited (CRISPR/Cas9) and Mutant (TILLING) Wheat

Wed, 01 Apr 2026 06:26:02 -0700

ABSTRACT

Field trials were conducted of wheat (Triticum aestivum) cv. Cadenza in which asparagine synthetase gene, TaASN2, had been knocked out, either on its own or together with a partial knockout of the related gene, TaASN1, using CRISPR/Cas9. Chemical mutagenesis (TILLING) TaASN2 nulls in the Claire background were also included. The main aim was to assess the free asparagine content of the grain and the conversion of free asparagine to acrylamide, a toxic contaminant, in bread, toast and biscuits. Over 2 years of trials combined, the TaASN2 and TaASN1/2 CRISPR knockouts resulted in a reduction of free asparagine in the grain of 59% and 93%, respectively, compared with Cadenza. The reduction in the TaASN2 total knockout TILLING line compared with Claire was 50%. Yield was not affected in the edited lines but was reduced in the TILLING lines. Acrylamide in bread made from a TaASN1/2 CRISPR line was below detection levels, while in a TaASN2 CRISPR line it was 14% of the Cadenza control. Even after 4 min of toasting, acrylamide levels remained at 8% and 23%, respectively, of the control. The concentration in bread made from the TILLING TaASN2 knockout was 21% that for the Claire control, rising to 46% after 4 min of toasting. Acrylamide in biscuits made from a TaASN1/2 CRISPR line was reduced by 93% compared with the control. The relationship between acrylamide and colour was altered in the edited and mutant lines compared with the controls, with less acrylamide forming for the same degree of colour.

Metabolic Reprogramming of a Phenolic Acid by a Plant P450 Monooxygenase Reverses Bacterial Immunosuppression

Tue, 31 Mar 2026 01:34:38 -0700

Ralstonia solanacearum suppresses P450 activity to block VA-to-VanA conversion, leading to VA accumulation and compromised immunity.

ABSTRACT

Soil acidification often exacerbates plant diseases caused by soil-borne pathogens like Ralstonia solanacearum, but the underlying molecular mechanisms remain elusive. This study unveils a sophisticated metabolic game in the tobacco-R. solanacearum pathosystem, where the pathogen manipulates host metabolism to suppress immunity, and the plant counteracts by enzymatically reprogramming a key metabolic signal. Using multi-omics approaches, we discovered that R. solanacearum infection induces a significant accumulation of veratric acid (VA) in tobacco. We demonstrated that VA acts as a potent immunosuppressant rather than a nutrient for the pathogen. It broadly inhibits plant pattern-triggered immunity, including flg22-induced ROS burst, and transcriptionally represses a suite of nucleotide-binding leucine-rich repeat (NLR) receptors, crucially including NtG28897 (NtTAO1). Silencing of NtTAO1 confirmed its pivotal role in resistance against Tobacco Mosaic Virus (TMV). Facing this metabolic sabotage, tobacco engages a counter-defence mechanism. We identified a specific cytochrome P450 monooxygenase (CYP86A22) that catalyses the conversion of the disease-promoting VA into vanillic acid (VanA). Transient overexpression of this P450 in Nicotiana benthamiana enhanced the in vivo conversion of VA to VanA. Crucially, this enzymatic conversion conferred strong resistance against TMV, whereas the P450 or VA alone did not. Our findings reveal a novel plant immune strategy ‘metabolic signal reprogramming’ where a P450 enzyme detoxifies a susceptibility metabolite into a defensive compound. This work provides a new paradigm for plant–pathogen interactions and identifies promising targets for metabolic engineering or green chemical strategies to achieve sustainable disease control.

The Transcription Factor OsWRKY64 Interacts With OsART1 to Positively Regulate Al Resistance in Rice

Tue, 31 Mar 2026 01:17:22 -0700

A proposed working model illustrating the cooperative regulation of Al tolerance by OsWRKY64 and OsART1 in rice. Under Al stress conditions in acidic soil, the transcription factor OsART1 directly binds to the promoter of OsWRKY64 to activate its transcription. The synthesized OsWRKY64 protein then physically interacts with OsART1 in the nucleus. This interaction positively regulates Al tolerance through two synergistic mechanisms: (1) OsWRKY64 stabilizes OsART1 protein by inhibiting its degradation via the 26S proteasome pathway; and (2) the OsWRKY64-OsART1 complex enhances the transcriptional activation of downstream target genes, including OsALS1, OsSTAR1, and OsFRDL4. The robust expression of these genes promotes cell wall modification and Al exclusion mechanisms, ultimately resulting in reduced Al accumulation in root tips and enhanced Al tolerance.

ABSTRACT

Rice (Oryza sativa) exhibits notable aluminium (Al) tolerance, as the C₂H₂-transcription factor OsART1 plays a crucial role in regulating Al tolerance in rice by modulating the expression of specific genes. However, the posttranscriptional regulation of OsART1 remains poorly understood. In this study, we identified and characterised OsWRKY64, which interacts with OsART1. OsWRKY64 was localised in the nucleus. Tissue expression analysis indicated that OsWRKY64 was primarily expressed in the roots, and its transcription and protein accumulation were significantly induced by Al. The oswrky64 mutants and the OsWRKY64 overexpression lines exhibited decreased or increased expression of genes regulated by OsART1, which consequently led to phenotypes sensitive or resistant to Al, respectively. Further analysis indicated that OsWRKY64 interacted with OsART1 to promote its stability, thereby accelerating the transcriptional activity of OsART1 on its downstream genes. Additionally, OsART1 upregulated OsWRKY64 expression by directly binding to the OsWRKY64 promoter, thus forming a negative feedback loop between OsART1 and OsWRKY64. Overall, our results demonstrated that OsWRKY64 influences Al resistance by interacting with and stabilising OsART1 to accelerate its transcriptional activity.

Functional Characterisation of HAIRPLUS (NtHAP) Genes Involved in Trichome Development and Specialised Metabolism of Tobacco

Mon, 30 Mar 2026 03:22:05 -0700

ABSTRACT

Plant glandular trichomes are specialised epidermal structures capable of synthesising, storing and secreting numerous varieties of secondary metabolites in different classes and are central to plant defence and the biosynthesis of high-value metabolites. In this study, we characterised the HAIRPLUS (HAP) gene family and uncovered its role as a conserved regulator of trichome development and metabolism in tobacco. Four homologues, NtHAP1a, NtHAP1b, NtHAP2a and NtHAP2b, were identified and functional studies using RNAi and CRISPR-Cas9 revealed that NtHAPs act as negative regulators of glandular trichome development. Suppression of NtHAPs resulted in increased trichome density and enlarged glandular heads, as well as enhanced accumulation of diterpenoids (e.g., neophytadiene) and increased nicotine levels. Additionally, NtHAP1 appeared to have a stronger effect on trichome density. This study establishes the NtHAP genes as key negative regulators of glandular trichome development in tobacco, expanding their functional scope from trichome morphogenesis to metabolic regulation and highlighting their evolutionary conservation across Solanaceae. These findings pave the way for both fundamental research into trichome biology and practical applications in metabolic engineering and crop improvement, such as pest resistance.

Beyond Starch: Towards a Scalable Potato Platform for Molecular Farming

Izabela Anna Chincinska, Dorota Sołtys‐Kalina, Audrey Y.‐H. Teh — Sun, 29 Mar 2026 00:00:00 -0700

Re-engineering potato as a biosafe and host-optimised platform for plant molecular farming by integrating intrinsic biological traits with targeted engineering strategies.

ABSTRACT

Thirty-five years after the first recombinant protein was produced in potato and 30 years after clinical trials of edible vaccines from its tubers, the crop is being reconsidered as a molecular farming chassis. Potatoes can accumulate recombinant proteins in tubers, enabling long-term storage and simplified logistics. Clonal propagation, access to minitubers and microtubers, and an established production infrastructure further distinguish the platform. Limited pollen dispersal and reliance on vegetative propagation also provide biosafety advantages. Despite these features, potato lost ground to other hosts due to low expression levels, high downstream processing (DSP) costs in water- and starch-rich tissues and limited scalability relative to seed-propagated crops. We review the technical and economic factors behind this decline and assess new opportunities to overcome them. Recent advances include refined expression cassettes, ER and secretory pathway engineering (including targeted glycoengineering), multigene stacking, genome editing and enzyme-assisted DSP. Seed-propagated diploid potatoes and alternative Solanum germplasm offer additional chassis options. Together with the emergence of start-ups revisiting potato as a production platform, these advances point to practical routes for re-evaluating its role in plant molecular farming. We argue that a rationally engineered, diploid-based ‘bioreactor potato’ could complement existing hosts and re-establish relevance in specific niches of next-generation biomanufacturing.

Deciphering Cold Stress Resilience: Multiomics Insights in Contrasting Wheat Genotypes From the Western Himalayas

Fri, 27 Mar 2026 21:28:05 -0700

ABSTRACT

Cold stress threatens wheat productivity, particularly in regions with extreme climatic conditions. To elucidate the molecular mechanisms underlying wheat's response to cold stress, we performed a multiomics analysis integrating lipidomics, transcriptomics, proteomics and metabolomics. Our study focused on two wheat genotypes with contrasting cold tolerance levels, SKAU_52 (tolerant) and SKAU_4301 (susceptible) to capture genotype-specific responses under cold stress. Lipidomic analysis revealed significant changes in lipid composition, with unsaturated lipids such as digalactosyldiacyl glycerols (DGDGs) and monogalactosyldiacylglycerols (MGDGs) upregulated in response to cold stress. These lipids are associated with maintaining membrane fluidity, whereas saturated lipids were downregulated in the cold-tolerant genotype. Transcriptomics analysis provides a strong evidence that cold tolerance in wheat is governed by coordinated activation of the ICE-CBF-COR regulatory cascade, with the cold-tolerant genotype ‘SKAU_52’ showing stronger and more sustained induction across pathway tiers than the cold susceptible wheat genotype ‘SKAU_4301’. Similarly, proteomic data highlighted differential abundance of proteins involved in antioxidative defence, osmotic adjustment and signal transduction, including late embryogenesis abundant (LEA) proteins. Metabolome assessment revealed substantial alterations in carbohydrate and amino acid metabolism, with sucrose and amino acids such as hydroxyproline identified as key contributors to cold tolerance. Additionally, defence hormones such as salicylic acid (SA), jasmonic acid (JA) and abscisic acid (ABA) exhibited genotype-specific regulation with higher accumulation in cold-tolerant genotype. Overall, this integrated multi-omics approach provides novel insights into the complex molecular mechanisms underlying cold stress adaptation in wheat, supporting the development of resilient wheat varieties capable of thriving in challenging cold environments.

Genomic and Transcriptomic Analyses Provide Insights Into Erysiphe necator Pathogenicity and Grapevine Response

Fri, 27 Mar 2026 20:34:34 -0700

ABSTRACT

Grapevine powdery mildew, caused by the fungus Erysiphe necator, is one of the most prevalent obligate biotrophic pathogens in vineyards, posing a significant threat to grape production. Despite its impact, research on E. necator pathogenicity and grapevine responses remains limited. In this study, we assembled a high-quality 69.93 Mb genome for E. necator isolate NAFU1, identifying 248 candidate-secreted effector proteins (CSEPs). RNA-Seq analysis of E. necator NAFU1 and the grapevine host during various infection stages revealed that expression of many genes, especially those encoding CSEPs, was induced in planta to facilitate host colonisation. Detailed analysis identified CSEP118 as a key highly induced effector gene, plays an important role in suppression of host defence. CSEP118 appears to interfere with the grapevine defence response to infection by targeting VviTrxz, a grapevine thioredoxin. Comparative transcriptome analysis of susceptible (Vitis vinifera cv. Cabernet Sauvignon) and resistant (Vitis piasezkii accession Baishui-40) grapevines upon infection by E. necator identified VviTCP14, encoding a transcription factor, to be a likely negative regulator of grapevine resistance against E. necator. Supporting this, VviTCP14-silenced plants exhibited increased expression of resistance-related genes such as those encoding stilbene synthases (STSs) and elevated stilbene contents when compared with the wild type grapevine. In summary, this study utilised a multi-omics approach to understand mechanisms underlying E. necator effector-triggered suppression of grapevine immunity and transcriptional regulation of host defence response during grapevine-powdery mildew interaction. The regulatory mechanisms uncovered in this study should provide valuable insights for improving grapevine resistance to powdery mildew.

Multisite Field Evaluation of Oil Accumulation and Agronomic Performance in Grain and Sweet Sorghums Engineered for Lipid Hyperaccumulation

Wed, 25 Mar 2026 09:25:38 -0700

ABSTRACT

Oil sorghum (OS) has been developed by engineering grain (TX430) and sweet (Ramada) genetic backgrounds to accumulate triacylglycerols (TAG) in vegetative tissues as an energy-dense feedstock for sustainable aviation fuel (SAF) and other biofuels. This study evaluated two TX430 OS lines (TxHO-2, TxHO-3) and two Ramada OS lines (RmHO-1, RmHO-2) alongside wild-type (WT) lines in NE and IL over 2 years (2023–2024) to quantify genotype × environment effects on agronomic performance and TAG accumulation. Across four environments, TX430 OS lines showed average TAG concentrations of 15.0 g kg⁻¹ in leaves and 12.8 g kg⁻¹ in stems, approximately 19-fold higher than WT. Ramada OS lines accumulated 26.1 g kg⁻¹ in leaves and 12.3 g kg⁻¹ in stems, approximately 25-fold and 13-fold increases over WT, respectively. OS lines in TX430 exhibited an 18% reduction in biomass (8.4 vs. 9.9 Mg ha⁻¹ for WT), while Ramada OS lines had similar WT biomass (18.3 vs. 19.9 Mg ha⁻¹ for WT). Among TX430 OS lines, TxHO-2 achieved the highest TAG yield (190 kg ha⁻¹), while RmHO-1 led the Ramada lines (335 kg ha⁻¹) due to higher biomass and similar TAG concentration. Enhanced TAG accumulation increased N, P, and K removal in TX430 lines but not in Ramada lines. Structural carbohydrate and ash concentration were unaffected. Overall, results confirm vegetative lipid accumulation as a viable strategy for high-biomass sorghum, supporting its potential as a dual-purpose feedstock for SAF. Future work should focus on minimizing biomass yield penalties and improving nutrient use efficiency in oil sorghum systems.

Structural Elucidation and Engineering of the (S)‐scoulerine 2‐O‐Methyltransferase Enabling Regioselective Epiberberine Biosynthesis in Coptis chinensis

Wed, 25 Mar 2026 04:57:23 -0700

ABSTRACT

Protoberberine alkaloids are a characteristic group of natural products in Coptis plants known for their notable pharmacological activities. However, the structural similarity and the substrate promiscuity of their biosynthetic enzymes have left the precise synthetic pathways remain unclarified, posing challenges to regulate product formation. In this study, we identified CcOMT8, a key enzyme responsible for C2-methoxylation in the biosynthesis of epiberberine in C. chinensis, through methyl jasmonate elicitation analysis and comparative genomics-based microsynteny analysis. Functional characterisation demonstrated that CcOMT8 specifically catalyses 2-O-methylation of (S)-scoulerine, as verified by heterologous expression in both microbial and plant systems. Its lack of activity toward (S)-cheilanthifoline further confirmed the specific route for epiberberine biosynthesis. Structural investigations of CcOMT8 and its complexes revealed key aspects of substrate recognition and a catalytic mechanism mediated by the His253-Asp254-Glu312 triad. Comparative structural analysis with 9-O-methyltransferases indicated that hydrophilic residues and reduced steric hindrance in the substrate binding pocket govern the regioselectivity of CcOMT8. Using focused rational iterative site-specific mutagenesis (FRISM), we developed an optimised mutant, S109L/C250A/L300A, with 4.88-fold enhanced catalytic efficiency. This study elucidates the biosynthetic pathway of epiberberine in Coptis, clarifies the molecular basis of enzyme-directed metabolic flux, and provides efficient biocatalysts for the synthetic biosynthesis of protoberberine alkaloids.

CitPH4 Confers Resistance to Citrus Canker by Activating Papain‐Like Cysteine Protease

Wed, 25 Mar 2026 04:40:15 -0700

ABSTRACT

Citrus canker, a devastating disease caused by Xanthomonas citri subsp. citri (Xcc), poses a significant threat to global citrus production due to the high susceptibility of nearly all commercial citrus cultivars to it. Although transcription factor Citrus PH4 (CitPH4) is well known for regulating fruit acidity, its potential role in plant immunity remains elusive. Here, we demonstrate that CitPH4 positively regulates citrus defence against Xcc. Transcriptomic and biochemical analyses indicate that CitPH4 binds to the promoter of the responsive to dehydration 21a (CsRD21a), a gene encoding a papain-like cysteine protease (PLCP), thus modulating its expression. Functional characterisation further reveals that CsRD21a is essential for CitPH4-mediated resistance to Xcc. Mechanistically, CsRD21a interacts with pathogenesis-related protein 5 (CsPR5) to promote salicylic acid (SA) accumulation. In addition, reciprocal activation of PLCP activity and SA signalling enhances immune defences against Xcc. Collectively, our findings reveal a CitPH4-mediated citrus immunity mechanism in which the CitPH4–CsRD21a–CsPR5 module constitutes a defence loop by integrating reciprocal activation effects of PLCP activity and SA signalling. This study provides a novel insight into the regulatory network of citrus resistance against Xcc, offering potential targets for breeding citrus cultivars with enhanced disease resistance and superior fruit quality.

Sweet Potato Gene Clusters Control Anthocyanin Biosynthesis and Leaf Morphology

Tue, 24 Mar 2026 23:37:13 -0700

ABSTRACT

Sweet potato (Ipomoea batatas) exhibits diversity in pigmentation and leaf morphology, yet the genetic architecture and regulatory organisation underlying these traits remain poorly resolved, particularly with respect to organ-specific control. We hypothesised that phenotypic variation is governed by clustered genetic modules comprising regulatory and structural genes operating in an organ-specific manner. To test this, we conducted genome-wide association studies (GWAS) using 4.6 million SNPs across 260 diverse accessions, integrated with transcriptomic, haplotype and functional analyses. GWAS identified two tandem clusters of MYB transcription factors on chromosome 5 as the primary regulators of leaf anthocyanin accumulation. Expression profiling, heterologous expression and transcriptional activation assays demonstrated that IbMYB2 and IbMYB3 function as key transcriptional activators and form a mutually reinforcing regulatory module. In contrast, pigmentation in storage roots was associated with a spatially distinct genomic region enriched in anthocyanin biosynthetic genes, including IbAOMT, Ib3GGT and IbLDOX, indicating different regulations between aerial and underground organs. Comparative genomic analysis further revealed expansion and conservation of MYB clusters in sweet potato, suggesting evolutionary selection for enhanced transcriptional control. In addition, GWAS uncovered a major locus on chromosome 7 controlling leaf shape variation. Functional analyses demonstrated that conserved developmental regulators, including BEL1-like (g29974), WD40 (g26165) and LMI1-like (g29859) genes, play causal roles in leaf margin development. CRISPR/Cas9-mediated knockout of g26165 directly reduced leaf lobing, confirming its functional importance. These findings reveal clustered regulatory and structural gene modules underlying key agronomic traits and provide insights into the genetic and evolutionary mechanisms driving phenotypic diversification in sweet potato.

A Bioluminescent Reporter System for Real‐Time Monitoring of the Unfolded Protein Response in Plants

Tue, 24 Mar 2026 05:30:12 -0700

ABSTRACT

The unfolded protein response (UPR) is a critical mechanism for maintaining endoplasmic reticulum (ER) homeostasis under stress. Here, we developed a bioluminescent reporter system, AtbZIP60-LUC, in Arabidopsis to dynamically monitor ER stress by coupling IRE1-mediated splicing of bZIP60 mRNA to firefly luciferase (LUC) expression. Under ER stress, IRE1 removes a 23-bp sequence from bZIP60u, producing a spliced bZIP60s transcript in-frame with LUC, enabling luciferin-dependent luminescence. Transgenic AtbZIP60-LUC lines exhibited specificity for canonical ER stressors (heat, DTT, tunicamycin) but not osmotic stressors (NaCl, mannitol), confirmed by bioluminescence, qPCR, and immunoblotting. Time-course assays revealed rapid LUC induction by DTT (peak at 1 h) and delayed activation by tunicamycin (peak at 1–2 h), followed by signal decline, reflecting adaptive UPR dynamics. Heat stress optimization identified 38°C as optimal, inducing robust LUC expression after 2–3 h without compromising viability, while 42°C caused irreversible damage. Genetic validation in ire1a ire1b mutants abolished LUC induction, confirming IRE1 dependency, whereas constitutive UPR activation via maize 16-kDa γ-zein (16γz) overexpression triggered LUC expression without stress. Extending this system to tobacco and tomato, we engineered NbbZIP60-LUC and SlbZIP60-LUC, which similarly responded to heat (38°C), DTT, tunicamycin, and ER-localized protein aggregation (16γz, zeolin) in transient and stable assays. This work establishes bZIP60-LUC as versatile, non-invasive tools for real-time UPR monitoring in plants, offering insights into ER stress dynamics and enabling cross-species studies of stress adaptation mechanisms.

Tuning Xylan Polymerisation Enhanced Fibre Digestibility Without Biomass Loss in Sheepgrass (Leymus chinensis)

Tue, 24 Mar 2026 04:54:17 -0700

ABSTRACT

Leymus chinensis (sheepgrass), a dominant perennial grass of the Eurasian Steppe, is a crucial source of carbohydrates and energy for ruminants. However, the lignocellulose recalcitrance severely limits its digestibility. Here, we targeted xylan, a major hemicellulose interacting with cellulose and lignin in cell wall. To improve digestibility, we knocked out two IRREGULAR XYLEM 14-LIKE (LcIRX14L) genes, which encode key enzymes for xylan biosynthesis. The Lcirx14L knockout mutants exhibited reduced xylan molecular weight but produced similar amounts of biomass to wild-type plants. Simon's staining and cellulase binding assays indicated enhanced cellulose accessibility in the Lcirx14L mutant. In addition, the Lcirx14L plant showed increased saccharification efficiency, dry matter and NDF digestibility, and production of volatile fatty acids by in vitro fermentation. This study thus provides novel insight for engineering forage grasses with both high yield and quality by modifying xylan polymerization.

Two Aquaporins Mitigate Growth‐Defence Trade‐Offs by Facilitating CO2 and H2O2 Transport in Wheat

Tue, 24 Mar 2026 02:46:08 -0700

ABSTRACT

The growth-defence trade-offs pose a major challenge to breeding high-yield and disease-resistant crops. Aquaporins are membrane channels that facilitate the transport of water and other small compounds, therefore regulating the growth-defence trade-offs. However, the molecular mechanism that governs the function of aquaporins in the trade-offs remains unclear. Here, we report that Triticum aestivum TaPIP1;6 and TaPIP2;10, aquaporins of the plasma membrane intrinsic protein (PIP) family, function as dual substrate channels that concurrently enhance plant growth and resistance to powdery mildew and English grain aphid. In wheat plants growing under normal conditions, TaPIP1;6 and TaPIP2;10 facilitate CO₂ transport from the atmosphere into wheat cells and promote photosynthesis, which leads to growth enhancement and grain yield increase. In wheat plants under attack by powdery mildew pathogen or English grain aphid, TaPIP1;6 and TaPIP2;10 function as concurrent H₂O₂ transport channels, mediating the influx of apoplastic H₂O₂ into the cytoplasm. In turn, the transported H₂O₂ activates innate immunity, including the MAPK cascade, callose deposition and defence gene expression, and thereby enhances wheat resistance to powdery mildew and the English grain aphid. In essence, co-overexpression of TaPIP1;6 and TaPIP2;10 exhibits synergistic effects on CO₂ and H₂O₂ transports, further amplifying both yield and resistance traits. Taken together, our results suggest that TaPIP1;6 and TaPIP2;10 function as dual-substrate transporting channels to promote growth by regulating CO₂ transport and to enhance resistance against pathogens and insects via H₂O₂-mediated immune responses. This finding provides crucial genetic targets for breeding crop varieties combining high yield with resistance traits.

Disruption of Asparagine Synthetase Is Associated to Increased Biomass in Lotus japonicus

Tue, 24 Mar 2026 02:15:34 -0700

ABSTRACT

Asparagine (Asn) constitutes the major form of nitrogen translocated within Lotus japonicus plants. In this work we use knock-out (KO) LORE1 mutants-deficient in the asparagine synthetase gene (LjASN1), which is the most highly expressed ASN gene in plants grown under non-symbiotic (NS) conditions, but much less expressed under symbiotic (S) conditions. The analysis of two different Ljasn1 homozygous mutant lines grown under NS or S conditions indicated that a much higher biomass was produced in Ljasn1 mutants grown under NS conditions compared to the WT (wild-type), whereas little difference with the WT was observed in mutant plants under S conditions. Metabolomic analysis revealed that Ljasn1 mutant plants are quite distinct to WT plants when grown under NS conditions, but not under S conditions. Asn levels were considerably reduced in Ljasn1 mutant plants compared to the WT when plants were grown under NS but not under S conditions. A general decrease in amino acids and an increase in carbon compounds, such as sugars and oxo-acids, was detected in NS roots and shoots, respectively, which may explain the growth phenotypes observed. RNAseq analysis showed changes related to oxidative metabolism under NS conditions, and C/N metabolism under S conditions. The data indicate that the LjASN1 deficiency produces important changes in the C/N balance and metabolite allocation of L. japonicus plants resulting in higher biomass content and lower Asn levels, two interesting traits for biotechnological crops engineering.

Production of the High Value Pharmaceutical Target, Human Granulocyte‐Colony Stimulating Factor, in Nicotiana benthamiana Is Improved by Co‐Expression of the Transcriptional Regulator of the Unfolded Protein Response, bZIP60

Fri, 20 Mar 2026 04:51:52 -0700

Plant Biotechnology Journal, EarlyView.

Single‐Cell CRISPR: An Efficient Strategy for Decoding Plant Cis‐Regulatory Complexity

Thu, 19 Mar 2026 05:49:22 -0700

ABSTRACT

The generation of complex traits involves the coordinated interplay of multiple gene networks. Elucidating the function of transcriptional cis-regulatory elements (CREs) in regulating gene expression is crucial for understanding complex regulatory pathways and improving our ability to modify macro-phenotypes. While traditional bulk sequencing approaches rely on tissue or cell population aggregates, single-cell transcriptomics provides a more precise perspective by capturing cell-type-specific information. The integration of single-cell technology with genome-wide genetic screening, particularly through the single-cell CRISPR (scCRISPR) system, enables the identification of critical regulatory elements and provides novel insights into gene-expression control mechanisms. Here, we summarise recent advances in diverse strategies for functional genome analysis using the scCRISPR system, with an emphasis on its potential to revolutionise single-cell genetic screening of CREs. We also explore the challenges and opportunities for applying these approaches in plant research.

StALKBH10B‐Mediated RNA m6A Modification Inhibits Potato Salt Tolerance by Targeting Flavonoids and ABA Signalling Pathways

Thu, 19 Mar 2026 01:21:40 -0700

ABSTRACT

N⁶-methyladenosine (m⁶A) is the most prevalent methylation modification present in mRNAs, which has been confirmed to participate in many developmental and biological processes. However, the biological function and specific regulatory mechanism of m⁶A modification in relation to salt tolerance of potato remain obscure. Here, we generated a transcriptome-wide m⁶A map using salt-resistant and salt-sensitive potato varieties under salt stress conditions to uncover patterns of m⁶A methylation in the potato response to salt stress. MeRIP-seq revealed that m⁶A is significantly enriched in the CDS region in potato, by recognising the conserved motifs including RRACH and URRUAY. Numerous differential m⁶A-deposited transcripts have been identified, which were significantly enriched in ABA-signalling and flavonoids biosynthesis pathway in two potato varieties after salt stress. Notably, a positive correlation was observed between the m⁶A enrichment and mRNA abundance based on combined analysis of MeRIP-seq and mRNA-seq. StALKBH10B was identified as an m⁶A demethylase for decreasing m⁶A modification levels, inhibiting mRNA stability and translation efficiency of ABA signal-related genes (StABF3, StAAO3, and StZEP7) and flavonoids biosynthesis genes (StPAL3, StCHS, and StFLS), and overexpression of StALKBH10B suppressed salt resistance in potato. Collectively, we uncover a novel mechanism of post-transcriptional modification involved in affecting salt stress response in potato, via StALKBH10B-mediated m⁶A demethylation on targeted transcripts in the ABA signalling and flavonoids biosynthesis pathway, thereby providing candidate genes for the breeding of stress-tolerant potato cultivars.

The ZmCOP1s–ZmCOL3 Module Enhances Late Flowering, Grain Yield and Grain Quality in Maize

Wed, 18 Mar 2026 05:35:32 -0700

ABSTRACT

Flowering time is a key determinant of yield and regional adaptation in crops and is largely controlled by light signalling. In this study, we identified two maize orthologs of Arabidopsis CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), designated ZmCOP1a and ZmCOP1b, which activate light signalling and reduce plant height. Loss-of-function mutants of ZmCOP1a and ZmCOP1b flowered early, whereas overexpression of either gene significantly delayed flowering under both long- and short-day conditions. Mechanistically, both ZmCOP1a and ZmCOP1b interacted with and stabilised the C2C2-CO-like transcription factor ZmCOL3. Together, they upregulated key repressors of flowering (ZmPRR37, ZmPRR95, ZmCCA1 and ZmCCT9), leading to suppression of florigen genes (ZCN7, ZCN8 and ZCN12) and floral meristem identity genes (ZMM3, ZMM4 and ZMM15). Field trials demonstrated that overexpression of ZmCOP1a or ZmCOP1b reduced starch content but increased protein levels, kernel numbers and kernel length, width and weight. In contrast, overexpression of ZmCOL3 decreased both starch and protein content. Collectively, our results demonstrate that the ZmCOP1s–ZmCOL3 module is a key regulator of flowering time and source–sink reallocation, providing valuable genetic targets for breeding high-yield, high-quality maize with optimised flowering time and enhanced carbon and nitrogen allocation.

Engineering a Gibberellin‐Switchable Dual‐Use Line Based on Ent‐Kaurene Oxidase Gene ZmKO1 Enables Two‐Line Hybrid Seed Production in Maize

Wed, 18 Mar 2026 05:28:48 -0700

ABSTRACT

Male-sterile systems are pivotal for maize hybrid seed production, yet existing systems are constrained by significant limitations. Here, we identified a novel single-gene-controlled recessive genic male sterility (GMS) mutant, defective in filament elongation 1 (def1), which exhibits non-elongated filaments, unopened glumes, and non-exserted anthers, yet undergoes normal microsporogenesis and produces viable pollen. Map-based cloning revealed that def1 is caused by a loss-of-function mutation in the ZmKO1 gene. Previous studies have identified ZmKO1 and ZmKO2 as the two putative KO-encoding genes in maize. Although heterologous expression evidence suggested that only ZmKO1 possesses KO activity, we demonstrate that both ZmKO1 and ZmKO2 are functional KOs for GA biosynthesis. The def1 mutant or ZmKO1 knockout lines exhibited reduced plant height during early seedling development but recovered rapidly to wild-type levels. In contrast, ZmKO2 knockout lines displayed severe dwarfism and pollen-less male sterility. These contrasting phenotypes demonstrate a clear functional divergence between the two genes. Utilising marker-assisted backcrossing and CRISPR/Cas9 editing, we generated ZmKO1-based GMS lines across diverse genetic backgrounds. These lines maintained stable male sterility and could be efficiently propagated via exogenous GA₃ application under different genetic backgrounds and environments, demonstrating robust “dual-use” properties. Data indicated that this dual-use trait has no significant effect on other agronomic traits of the male sterile line and its derived hybrid combinations. Based on this, we established a novel two-line hybrid seed production system in maize, termed the Gibberellin-switchable Dual-use Line (GDL), and successfully applied it in the hybrid seed production of Chuandan 99.

Three Decades of China's Bt Cotton: Achievements and Insights

Wed, 18 Mar 2026 05:09:19 -0700

ABSTRACT

Cotton is a vital natural fibre crop with significant economic value worldwide. In response to the threat of cotton bollworm (Helicoverpa armigera), the China government initiated a research project in 1992 to develop transgenic Bacillus thuringiensis (Bt) cotton. Through domestic research and development efforts, China achieved a significant milestone in 1994: the successful development of Bt cotton. The project has continued since then, consistently advancing agricultural plant breeding efforts and providing economically critical new cotton germplasm to combat insect infestation and other stressors. We here present an overview of the 30-year history of this project, highlighting eight important lessons, six significant achievements, and three valuable insights gleaned from the pioneering agricultural endeavour. Chinese Bt cotton revolutionised the country's cotton industry and contributed to the economic growth and sustainability of Chinese agriculture. Through careful analysis and reflection, this article provides guidance for future development and implementation of agricultural biotechnologies.

SlMYB17 Antagonises the SlCBF Pathway to Negatively Regulate Tomato Chilling Tolerance

Wed, 18 Mar 2026 04:51:24 -0700

ABSTRACT

Low temperature is a significant environmental constraint, impeding the extensive cultivation of tropical plants. Here, we identify the transcription factor SlMYB17 as an important negative regulator of tomato chilling tolerance. Overexpression of SlMYB17 significantly reduced chilling tolerance, whereas slmyb17 mutants exhibited enhanced tolerance. ChIP-seq analysis revealed that SlMYB17 targets genes involved in diverse biological processes and stress responses, suggesting its role in coordinating plant development and stress adaptation. SlMYB17 directly binds to the promoters of cold-regulated (COR) genes, such as SlCOR27b and WCOR413, thereby inhibiting their expression. Crucially, protein–protein interaction studies and Dual-LUC assays demonstrated that SlMYB17 interacts with SlCBF1, SlCBF2, and SlCBF3 in the nucleus to inhibit SlCBF-mediated activation of COR genes. Using virus-induced gene silencing (VIGS) targeting SlCBF1-3 in wild-type and slmyb17 mutants, we demonstrate genetically that SlMYB17's function in chilling tolerance is dependent on SlCBFs. Collectively, SlMYB17 antagonises the SlCBF pathway at both transcriptional and protein activity levels, ultimately suppressing tomato chilling tolerance. Our work establishes slmyb17 mutants as valuable genetic resources for developing chilling-tolerant tomato varieties, and the ChIP-seq data provide important insights for studying MYB transcription factors in stress responses and development.

Analysis of BpbHLH Gene Family Responsive to MeJA Signalling in Betula platyphylla Suk. and Functional Mechanisms of BpbHLH42/44 in Genetic Improvement and Triterpenoid Biosynthesis

Tue, 17 Mar 2026 05:16:27 -0700

ABSTRACT

The basic helix–loop–helix (bHLH) transcription factor family regulates plant secondary metabolism, development and stress responses. Although triterpenoids such as betulinic acid (BA), betulin (BT) and oleanolic acid (OA) from Betula platyphylla Suk. are of pharmacological importance, the methyl jasmonate (MeJA)-induced regulation of IVa bHLHs remains unclear. A total of 131 BpbHLH genes were identified, and functional characterisation was performed for two IVa members, BpbHLH42 and BpbHLH44, in yeast, tobacco, birch cells and transgenic plants. Both enhanced triterpenoid biosynthesis but exhibited distinct specificities: BpbHLH42 primarily promoted OA accumulation by activating BpHMGR, BpSE1/3, BpW and BpY6, while BpbHLH44 favoured BT production through BpW, BpY6 and BpY11. Both indirectly regulated BpY9 via BpMYB21, forming a bHLH–MYB complex, and the MeJA repressor BpJAZ2 disrupted the BpbHLH42–MYB21 interaction. Transgenic birch lines further revealed divergent phenotypes: BpbHLH42 overexpression enlarged and smoothed leaves and increased OA levels, whereas BpbHLH44 enhanced alkali stress tolerance by elevating secondary metabolite accumulation. These results uncover the differential regulatory roles of BpbHLH42 and BpbHLH44 in triterpenoid biosynthesis and demonstrate their potential for metabolic engineering and genetic improvement in woody plants.

Efficient Transgene‐Free Multiplexed Germline Editing via Viral Delivery of an Engineered TnpB

Tue, 17 Mar 2026 05:10:26 -0700

Plant Biotechnology Journal, EarlyView.

A Conserved Magnaporthe oryzae Effector Counteracts the Rice Ubiquitin‐Proteasome System by Disrupting the E2 Function to Suppress Immunity

Mon, 16 Mar 2026 05:29:49 -0700

ABSTRACT

Pathogens commonly secrete effectors into host cells to facilitate invasion. In the host ubiquitin-proteasome system (UPS), E3 ubiquitin ligases often target pathogen effectors for degradation, thereby enhancing immune responses. In turn, pathogen effectors frequently disrupt E3 ligase function to promote virulence. However, it remains largely unclear whether pathogen effectors also interfere with other enzymes of the UPS, such as E2 ubiquitin-conjugating enzymes. In this study, we identified a conserved effector, MoCE1, that is essential for the pathogenicity of Magnaporthe oryzae. MoCE1 is secreted into rice cells, where it interacts with the rice E3 ligase OsRING10 and the E2 enzyme OsUBC11. Upon M. oryzae infection, OsRING10 and OsUBC11 act synergistically to degrade MoCE1 through K48-linked polyubiquitination. Overexpression of either OsRING10 or OsUBC11 enhances resistance to M. oryzae. To counteract this defence, MoCE1 inhibits the enzymatic activity of OsUBC11. Collectively, these findings reveal a nuanced mechanism in which a pathogen effector, regulated by a host E2–E3 pair, disrupts E2 function to escape UPS-mediated immunity in plants.

A Hierarchical VvbHLH30‐VvERF70‐VvACS2 Module Orchestrates Ethylene Biosynthesis and Cold Adaptation in Grapevine

Mon, 16 Mar 2026 02:39:46 -0700

ABSTRACT

Ethylene is a key gaseous phytohormone that plays crucial roles in regulating plant growth, development and stress responses. However, ethylene-associated biosynthetic and transcriptional regulatory mechanisms governing cold-adaptation responses in plants remain poorly understood. In this work, genome-wide analysis from grapevines (Vitis vinifera) identified nine ACS family members, of which VvACS2, VvACS4 and VvACS6 exhibited the most dynamic transcriptional responses to cold stress and were chosen for functional validation. CRISPR-Cas9-mediated knockout and overexpression experiments revealed that VvACS2 is the major contributor to ethylene biosynthesis during cold stress in grapevine roots. Screening time-course cold treatment data from Vitis vinifera and Vitis amurensis roots identified VvERF70 and VvbHLH30 as the only two TFs, among six candidates, that directly regulate VvACS2 expression. Overexpression and CRISPR-Cas9-mediated knockout of VvERF70 or VvbHLH30 in roots further confirmed their contribution to enhanced ethylene production and cold tolerance under low-temperature treatment. Furthermore, the induction of VvACS2 was greatly enhanced when VvERF70 dimerized with VvbHLH30. Notably, VvbHLH30 further positively regulates ethylene biosynthesis under cold stress by interacting with VvERF70 and binding to its promoter. Taken together, we define a hierarchical transcriptional regulatory network where the VvbHLH30-VvERF70-VvACS2 module is pivotal for ethylene biosynthesis and underpins grapevine cold tolerance. This work provides new mechanistic insights into cold adaptation mechanisms and offers novel strategies to mitigate frost damage in agricultural crops.

Telomere to Telomere Genome Assembly and Efficient Transformation and Genome Editing in Populus euphratica

Sat, 14 Mar 2026 02:30:01 -0700

Plant Biotechnology Journal, EarlyView.

A Near Telomere‐to‐Telomere Genome of Belamcanda chinensis Provides Insights Into Genome Evolution and the Biosynthesis of Characteristic Isoflavones

Sat, 14 Mar 2026 02:15:40 -0700

ABSTRACT

Belamcanda chinensis is a non-leguminous medicinal plant rich in bioactive isoflavones; however, the lack of a high-quality reference genome has limited elucidation of its isoflavone biosynthetic and modification network. Here, we present the first near telomere-to-telomere genome assembly of B. chinensis (4.18 Gb), generated using Illumina survey reads, PacBio HiFi and Oxford Nanopore long reads, and Hi-C scaffolding, achieving high completeness and accuracy (assembly BUSCO: 98.70%; LAI: 17.2). Ks/synteny-depth analyses and fossil-calibrated dating, with calibration at four fossil nodes, indicate two lineage-specific WGD events (~54.6 and ~27.3 MYA). These events drove significant expansions of key gene families involved in stress response and secondary metabolism. Leveraging this genome, we identified two key O-methyltransferases (BcOMT03 and BcOMT33), which are responsible for catalysing the biosynthesis of quality-marker compound irisflorentin. Meanwhile, BcUGT009, BcUGT119, BcUGT124, and BcUGT032 were characterised as glycosyltransferases with 7-O catalytic activity. Structural modelling and site-directed mutagenesis further elucidated the catalytic mechanism of BcUGT009, and its K404A mutant exhibited a significant increase in relative activity. Cross-species comparative analyses further revealed that convergent expansion of these key enzyme families underlies isoflavone biosynthetic capacity in both leguminous and non-leguminous plants. This study not only reveals the ancient polyploidization events of B. chinensis, the amplification of lineage-specific gene families and the biosynthetic pathway of characteristic isoflavones, but also provides a reference genome and functionally validated tailoring enzymes that will facilitate future heterologous pathway reconstruction and metabolic engineering of these isoflavones.

Gallic Acid‐Responsive microRNAs Reprogram Lignification During Drought Acclimation Process in Spearmint

Sat, 14 Mar 2026 02:09:39 -0700

ABSTRACT

Mentha spicata L. (spearmint) is a high-value aromatic and medicinal species, whose productivity is strongly affected by water deficit. Nevertheless, the molecular mechanisms underlying drought acclimation in this mint remain largely unexplored. Thus, here, we investigated the microRNA-mediated regulatory processes triggered in M. spicata under drought stress (DS) and following treatment with gallic acid (GA), a natural phenolic compound that our research group has already documented to be a potential biostimulant for spearmint. A small-RNA sequencing approach revealed that both DS and GA induced substantial changes of the expressed miRNome, modulating 35 microRNAs (e.g., miR397a, miR159a, miR172b) whose predicted targets (e.g., Laccase-2, MYB transcription factors) are known to be involved also in lignin production. In detail, DS induced upregulation of lignin biosynthetic genes, enhancement of Laccase activity, and shifting in lignin monomer composition, promoting the putative reinforcement of the cell wall as expected during water deficiency. Conversely, GA treatment attenuated DS-induced stress, regulating microRNA-mRNA modules which balanced phytochemical and hormonal response while maintaining controlled lignification and optimising xylem function. These results highlight the pivotal role of microRNAs in orchestrating drought acclimation in M. spicata and identify GA as a compensatory agent under water-limiting conditions, capable of fine-tuning growth, cell wall remodelling, and redox homeostasis. Collectively, our findings provide molecular insights into biostimulant-mediated stress resilience and identify GA treatment as a promising biotechnological strategy to improve drought tolerance in Lamiaceae crops.

A Natural LTR Retrotransposon Insertion in the Promoter of GhNAC140‐Dt Boosts Cotton Lint Yield

Fri, 13 Mar 2026 07:02:51 -0700

ABSTRACT

Transposable elements (TEs) are fundamental drivers of crop evolution and domestication. Whereas the underlying mechanisms of TE-mediated gene activation remain poorly understood. Lint percentage is an important yield component in cotton. Here, we report a retrotransposon insertion in the promoter of GhNAC140-Dt, a secondary wall NAC encoding gene, to promote the lint production by elevating its expression. We confirm that a 60 bp core cis-regulatory module within the TE's LTR (long terminal repeat) specifically recruits the transcription factor GhMYB46 and increases downstream genes' expression. GhNAC140-Dt overexpression activates the expressions of secondary cell wall development related genes, including GhCESA4-Dt, GhCESA4-At, and GhCOBL9-At, promotes cellulose deposition, and enhances lint percentage. This retrotransposon insertion massively emerges on the domestication transition from Gossypium hirsutum races to cultivated cotton accessions, with > 80% fixation in modern cultivars. This work deepens our understanding of TE-mediated gene activation; it also provides direct molecular evidence for “transposon-driven yield evolution” in crop domestication.

FvMAPK6‐Mediated FvMYB44s/FvSWEET1 Dual‐Layer Regulation Modulates Sugar Accumulation in Strawberry Fruit, With FvSPS3 Enabling Quality–Yield Balance

Fri, 13 Mar 2026 06:55:48 -0700

ABSTRACT

Sugar content is a key determinant of fruit quality, and sugars also act as signalling molecules that regulate ripening processes, including anthocyanin accumulation. However, the molecular mechanisms underlying sugar accumulation and sugar signal-mediated ripening remain incompletely understood. In this study, we identify FvMAPK6 as an important phosphorylation hub that coordinates both sugar and anthocyanin accumulation in strawberry fruit. FvMAPK6 forms a phosphorylation cascade with FvMAPKK4, which directly phosphorylates the transcription factors FvMYB44.1 and FvMYB44.2. This phosphorylation reduces the stability and transcriptional activity of these proteins, attenuates their repression of downstream target genes such as FvCHI, FvSPS3 and FvSWEET1, thereby coordinating anthocyanin and sugar accumulation. Furthermore, FvMAPK6 increases the protein abundance of the hexose transporter FvSWEET1 in strawberry fruits and alters its transport activity through phosphorylation. We demonstrate that sucrose treatment activates FvMAPK6, reinforcing its regulation of FvMYB44s and FvSWEET1 and thus amplifying sugar and anthocyanin accumulation. These findings establish FvMAPK6 as a key regulator that integrates both sugar accumulation and signalling at both transcriptional and post-transcriptional levels. Although FvMAPK6 promotes sugar accumulation, it significantly reduces fruit yield and vegetative growth. To overcome this limitation, we screen for downstream targets of FvMAPK6 and identify FvSPS3 as a promising breeding target: modulating FvSPS3 improves fruit quality without compromising vegetative growth or yield. Collectively, our findings reveal novel regulatory pathways modulating sugar accumulation and signalling in strawberry while providing a valuable molecular target for the simultaneous improvement of fruit quality and agricultural productivity.

Chromosome‐Level Genome Assembly of the Allotetraploid Gynostemma pentaphyllum Provides Novel Insights Into the Biosynthesis of Ginsenoside and Gypenoside LVI

Fri, 13 Mar 2026 01:25:33 -0700

ABSTRACT

Gynostemma pentaphyllum, a herb used in tea and traditional Chinese medicine, shows geographic variation in its production of valuable dammarane-type ginsenosides and gypenoside LVI between populations from Suining (SN) and Nanning (NN). To elucidate the mechanisms underlying this differential metabolite accumulation, a chromosome-level genome for G. pentaphyllum (SN population) was assembled. The analysis revealed that SN is a tetraploid (~1.2 Gb), resulting from a recent whole-genome duplication event in a diploid ancestor. Phylogenetic analysis indicates SN and diploid NN share a recent common ancestor, diverging approximately 4.95 million years ago. Chromosome evolution analysis confirmed SN is an allotetraploid with clear subgenomic differentiation. This genome, combined with multi-omics data, enabled the screening of candidate P450 genes involved in ginsenoside/gypenoside LVI biosynthesis. In vivo and in vitro experiments confirmed that GpCYP88AB3 functions as a bifunctional enzyme by first hydroxylating dammarenediol-II at C-12 to yield protopanaxadiol (PPD), and then hydroxylating PPD at C-2 to form 2α-OH-PPD. Phylogenetically, GpCYP88AB3 and similar enzymes from Araliaceae belong to distinct CYP subfamilies, demonstrating convergent evolution of this function between the two plant families and highlighting the functional plasticity of P450s. Evolutionary analysis suggests that GpCYP88AB3 emerged from a CYP88 gene family expansion in the tetraploid G. pentaphyllum. This expansion occurred after, but was not directly caused by, the whole-genome duplication event. This study elucidates the biosynthetic pathway for the key metabolites in G. pentaphyllum, providing a foundation for future metabolic engineering and synthetic biology applications.

Cross‐Species Reprogramming of Developmental Plasticity and Metabolic Rewiring via Banana‐Derived WUS2 Developmental Regulator

Roni Chaudhary, Surender Singh, Usman Ali, Siddharth Tiwari — Thu, 12 Mar 2026 06:54:54 -0700

ABSTRACT

Plant regeneration is governed by intrinsic gene regulation and phytohormonal cues. WUSCHEL (WUS) gene promotes regeneration, but its broader functional role remains unexplored. Here, we demonstrate that the constitutive and inducible expression of banana-derived WUS2 (GN-WUS2) enhances regeneration in Nicotiana tabacum (tobacco) and Musa acuminata (banana) cv. Grand Naine, even in hormone-free MS medium. Constitutive (CaMV35S::GN-WUS2) expression promoted shoot formation and modulated hormonal and morphogenic gene expression, as evidenced by molecular, biochemical and histological analyses. However, it caused some pleiotropic effects. To overcome this, glucocorticoid receptor-based inducible GN-WUS2 expression enabled healthy shoot development. The upregulated expression of HMGR1, IPPI2 and SMT1-2 in transgenic tobacco lines boosted isoprenoid and phytosterol biosynthesis and correlated with increased cell division, biomass, pod size and seed yield. Proteomic analysis of seeds from transgenic tobacco lines revealed an enrichment of lipid-associated proteins and the accumulation of the novel lipid adipic acid, supported by expression profiling of NtKA and NtSA genes. Collectively, these results establish GN-WUS2 as a master regulator that integrates developmental reprogramming with novel phytosterol biosynthesis and yield enhancement, presenting its versatile role in next-generation regeneration and crop improvement.

Mechanical Strength: An Unrecognised Target in the Genetic Improvement of Crops

Wed, 11 Mar 2026 21:40:36 -0700

ABSTRACT

Leaf angle (LA) is a crucial agronomic trait influencing planting density and crop yield. Previous research highlighted the importance of cellular variations in the ligular region for determining LA, but the underlying regulatory mechanisms remain unclear. Here, we demonstrate LA is not a static trait, but rather represents a dynamic equilibrium between mechanical forces maintaining leaf erectness and those promoting blade drooping. To quantify the drooping tendency, we introduce gravitational moments, which show positive correlations with LA, blade length (BL) and blade weight (BWt). Notably, the mechanical forces are tightly regulated by the sheath layers surrounding the stalk and by the thickness and lignin deposition on the ligular region of sclerenchyma (SC) cells. Furthermore, we applied single-nucleus transcriptome analyses (snRNA-seq) to construct a comprehensive transcriptional atlas spanning the ligular regions of compact-type (Z58), intermediate-type (B73) and expanded-type (W22) inbred lines. Through the comparative analysis of snRNA-seq and RNA-seq of three inbred lines, we identified the adaxial hypodermis (HP) cells as pivotal sites where lignin biogenesis and metabolism genes were specifically expressed in compact-type Z58, consistent with the lignin deposition pattern. Notably, we discovered that the NAM, ATAF and CUC (NAC) transcription factor-encoding genes NAC secondary wall thickening promoting factor 2 (NST2) and NST3, which mediate lignin biogenesis in the ligular region, especially on the adaxial side, play key roles in reinforcing mechanical support and reducing LA. Collectively, this study advances our understanding of ligular development and LA regulatory mechanisms and provides strategic insights for breeding crops with improved agricultural productivity.

OsRALF26 Serves as an Endogenous Signal Recognised by XA21 to Promote Robust and Distal Resistance in Rice

Oh‐Kyu Kwon, A‐Ram Jeong, Chang‐Jin Park — Wed, 11 Mar 2026 06:41:20 -0700

ABSTRACT

Plant immune receptors detect both microbe-derived and endogenous signals to activate defences. XA21, a rice immune receptor, confers strong race-specific resistance to a subset of Xanthomonas oryzae pv. oryzae (Xoo) strains by recognising the microbial sulphated peptide RaxX. However, the molecular basis for the notably robust XA21-mediated immune response has remained unclear. Here, we report that the small secreted peptide OsRALF26, previously identified as an Oryza-specific ligand for FERONIA-like receptor 1 (OsFLR1), is also directly perceived by XA21. Recognition of OsRALF26 by XA21 triggers a pronounced reactive oxygen species (ROS) burst, pathogenesis-related (PR) gene induction, and enhanced resistance to Xoo. Notably, silencing OsRALF26 leads to a spatially biased reduction in XA21-mediated resistance, particularly in distal tissues. These findings identify OsRALF26 as a host-derived ligand of XA21 that is required for full activation of XA21-mediated immunity in distal tissues, consistent with a role for OsRALF26 in spatial propagation of XA21-dependent defence. By integrating microbe-derived and endogenous signals, XA21 exemplifies a versatile immune strategy in rice. This dual recognition may have arisen through the introgression of XA21, which unintentionally conferred OsRALF26 responsiveness—thereby reinforcing immune robustness in rice varieties.

The BAHD Acyltransferase Gene Family: Evolutionary Dynamics, Biochemical Mechanisms, and Roles in Plant Stress Adaptation

Wed, 11 Mar 2026 00:00:00 -0700

BAHD acyltransferases drive metabolic diversification in plants by coupling conserved catalytic scaffolds with regulatory flexibility, enabling stress adaptation and ecological specialisation.

ABSTRACT

BAHD acyltransferases constitute one of the most versatile enzyme superfamilies in plants, catalysing the acylation of alcohols, amines, polyamines, and phenolic compounds to generate an extraordinary diversity of specialised metabolites. Initially identified through a limited number of anthocyanin- and alkaloid-modifying enzymes, BAHDs are now recognised as key regulators of phenylpropanoid flux, cutin and suberin polymerisation, volatile ester biosynthesis, and the stabilisation of acylated flavonoids. Comparative genomic analyses classify BAHD proteins into eight clades that share conserved catalytic motifs yet display pronounced functional divergence, reflecting a balance between deep evolutionary conservation and lineage-specific innovation. Recent structural and biochemical studies demonstrate how subtle active-site modifications govern substrate promiscuity and specialisation, enabling rapid metabolic reprogramming during environmental stress. Omics-based investigations further reveal widespread induction of BAHD genes under drought, salinity, heat stress, pathogen attack, and herbivory, linking BAHD activity to cell wall reinforcement, phenolamide biosynthesis, anthocyanin acylation, and ecological signalling. Beyond their physiological roles, BAHD acyltransferases have emerged as attractive targets for metabolic engineering, synthetic biology, and crop improvement, where manipulation of specific family members enhances stress tolerance, biomass quality, and nutritional or industrial value. Here, we integrate evolutionary, structural, and regulatory insights into BAHD function, highlight emerging translational opportunities, and discuss challenges associated with functional redundancy, substrate promiscuity, and biosafety considerations. Collectively, this synthesis positions BAHD acyltransferases as central mediators of plant adaptation and as promising tools for sustainable agriculture and biotechnological innovation.

Transgenic Lepidopteran‐Pests‐Resistant and Herbicide‐Tolerant Cotton Through Transfer of Cry1Ab‐vip3Aa and Cp4‐epsps+bar Genes

Qi Mou, Jun Zhang, Zhanfeng Si, Shangkun Jin, Wanying Zhang, Tianzhen Zhang — Tue, 10 Mar 2026 09:20:48 -0700

Plant Biotechnology Journal, EarlyView.

The Advantaged Salt Inducible Suaeda salsa SsNRT2.5 and Its Promoter Significantly Enhance Nitrate Transport Efficiency and Salt Tolerance in Transgenic Arabidopsis and Rice

Tue, 10 Mar 2026 08:57:29 -0700

ABSTRACT

Efficient nitrogen (N) uptake is critical for crop yield, but soil salinization inhibits plant nitrogen acquisition. In this study, the nitrate (NO₃ ⁻) transporter gene SsNRT2.5 and its promoter from the halophyte Suaeda salsa was investigated to elucidate the functional role in NO₃ ⁻ transport under salinity and low NO₃ ⁻–N conditions. SsNRT2.5 and its promoter were cloned and transformed into Arabidopsis thaliana and rice (Oryza sativa L.) for functional identification, which included analyses of expression patterns, promoter cis-element characterisation and phenotypic assessments under salt and low NO₃ ⁻–N conditions. SsNRT2.5 expression was significantly upregulated under salt stress and low NO₃ ⁻–N conditions in S. salsa, which improved NO₃ ⁻ transport in trangenic Arabidopsis thaliana and rice. Its promoter contained salt-responsive (e.g., GT-1, DRE) and N-related (e.g., GATABOX) elements, which drove stronger salt-induced NRT2.5 expression than AtNRT2.5 promoter. Transgenic Arabidopsis and rice with SsNRT2.5 and its promoter showed enhanced NO₃ ⁻ accumulation, reduced Na⁺ toxicity, and higher salt tolerance, as well as improved seed NO₃ ⁻ storage and viability compared to WT. SsNRT2.5 plays a key role in the adaptation of S. salsa to high saline and nitrogen-limited environments, offering valuable genetic resources and theoretical insights for breeding salt-tolerant crops and developing sustainable saline agriculture.

Metabolic Enzyme MeHNL11 Regulates MeCAS1b Transcription for Cyanide Reutilization in Response to Nitrate Deficiency in Cassava

Tue, 10 Mar 2026 08:38:06 -0700

ABSTRACT

Cassava (Manihot esculenta Crantz) exhibits exceptional tolerance to infertile soils and contains abundant cyanogenic glucosides (CGs). Previous research has indicated that CGs can serve as a significant reservoir of organic nitrogen in plants. However, the extent to which its high-CG content contributes to efficient nitrogen utilisation and adaptation to low nitrogen (N) in cassava remains to be further elucidated. This study represents the first identification of MeHNL11 as a bifunctional protein. In response to N deficiency, the hydroxynitrile lyase activity of MeHNL11 promotes the generation and accumulation of cyanide and the Cys245 residue of MeHNL11 is critical for its nuclear oligomerization, in which the protein functions as a transcription factor. Following the cyanide transmission into the nucleus, the oligomeric form of MeHNL11 dissociates into monomers, leading to a dramatic upregulation of MeCAS1b transcription. This regulatory mechanism helps sustain intracellular cyanide homeostasis within cassava and facilitates the synthesis of primary N metabolites, thereby alleviating N deficiency. The exogenous application of the cyanide antidote hydroxocobalamin (COB) inhibited cyanide assimilation by MeCAS1b, leading to exacerbated N deficiency symptoms, such as leaf yellowing and a significant reduction in the contents of NH₄ ⁺ and free amino acids (AA) in cassava seedlings under low-N conditions (LN). Our research demonstrates that the MeHNL11-MeCAS1b module plays a pivotal role in CG recycling, offering new insights into the underlying mechanisms governing cassava's exceptional tolerance to low N stress.

MdRLKT1–MdRAX2–MdMKS1 Module Positively Regulating Resistance to Cytospora mali in Apple

Yanan Tang, Guangyao Li, Yang Li, Yuzhu Wang, Hao Feng, Lili Huang — Tue, 10 Mar 2026 00:00:00 -0700

ABSTRACT

Valsa canker (caused by Cytospora mali = Valsa mali. C. mali) is one of the most destructive diseases affecting apple cultivation. The scarcity of natural germplasm resources with high resistance and immunity underscores the importance of exploring plant immune regulation factors of disease-resistant breeding. Protein post-translational modifications, particularly phosphorylation, are critical regulatory mechanisms in plant immunity. This study investigates how the apple receptor-like kinase MdRLKT1 modulates resistance to Valsa canker through the phosphorylation of the transcription factor MdRAX2. We found that MdRLKT1-interference (RNAi) transgenic lines exhibit increased susceptibility to C. mali infection compared to wild-type controls, indicating that MdRLKT1 positively regulates apple immune responses. Notably, MdRLKT1 interacts with the MYB transcription factor MdRAX2, facilitating its translocation into the nucleus. In vitro phosphorylation assays identified serine 147 (Ser147) as the phosphorylation site of MdRAX2 by MdRLKT1. Mutant MdRAX2^S147A, with this phosphorylation site inactivated, demonstrated reduced resistance to C. mali. Further analysis revealed that MdRAX2 binds to the promoter region of MdMKS1, transcriptionally repressingits expression, whereas MdRAX2^S147A failed to regulate MdMKS1 transcriptionally. Overexpression of MdMKS1 in apple resulted in reduced resistance to C. mali, suggesting that MdMKS1 negatively regulates apple immunity. These findings establish that the MdRLKT1-MdRAX2-MdMKS1 module plays a positive regulatory role in enhancing apple resistance to C. mali. In conclusion, MdRLKT1 activates the transcriptional repressor function of MdRAX2 through phosphorylation, thereby alleviating the negative regulatory effect of MdMKS1 on disease resistance and ultimately boosting the defensive capabilities of apple against pathogens.

A Near Gap‐Free Haplotype‐Resolved Genome Assembly of Zoysia japonica Uncovers Intra‐Subgenomic Gene Expression and Regulatory Variation

Sae Hyun Lee, Preethi Purushotham, Ambika Chandra, Murukarthick Jayakodi — Mon, 09 Mar 2026 23:25:19 -0700

Plant Biotechnology Journal, EarlyView.

LsMAPK6 Phosphorylates the LsCO Protein to Enhance Its Stability and Transcriptional Activity, Promoting Floral Transition Upon High Temperatures in Lettuce

Sat, 07 Mar 2026 05:30:31 -0800

ABSTRACT

High temperatures significantly accelerate the timing of floral transition, namely, bolting and flowering, in lettuce, which results in severe loss of marketable yield. Thus, understanding the genetic regulation of floral transition is of great interest to plant biologists and lettuce breeders. Here, we show that mitogen-activated protein kinase (LsMAPK6), whose expression and phosphorylation are stimulated by elevated temperatures, plays a positive role in the floral transition. The lsmapk6 mutants exhibit delayed bolting and flowering, whereas LsMAPK6 overexpression accelerates lettuce bolting. LsMAPK6 physically interacts with LsCO. Knockout of LsCO, to a large extent, phenocopies lsmapk6 mutants, strongly indicating that they function in the same genetic pathway. Mechanistically, LsMAPK6 phosphorylates LsCO at residue serine-258, resulting in the enhanced transcriptional activity and protein stability of LsCO and consequently the activation of LsFT-mediated flowering signalling pathways, which was confirmed by phospho-inactive and mimic analyses. Collectively, these findings reveal that the LsMAPK6-LsCO signalling module fine-tunes the timing of floral transition upon high temperatures, demonstrating that LsMAPK6 is a potential target for breeding lettuce cultivars adapted to global warming.

ZmWRKY29 Transcriptionally Represses ZmRBOHC to Attenuate ROS Production and Facilitates Gibberella Stalk Rot Susceptibility in Maize

Fri, 06 Mar 2026 20:36:13 -0800

ABSTRACT

Gibberella stalk rot (GSR), caused by the fungal pathogen Fusarium graminearum, severely threatens maize production. However, the molecular mechanisms underlying maize resistance to GSR remain poorly understood. Here, we have identified ZmWRKY29 as a transcriptional repressor induced by F. graminearum infection, which negatively regulates maize resistance to GSR. Overexpression of ZmWRKY29 significantly compromised GSR resistance with a marked reduction in reactive oxygen species (ROS) production and callose deposition, while its mutation enhanced resistance and elevated ROS accumulation. RNA-seq revealed that the expression levels of two respiratory burst oxidase homologues, ZmRBOHA and ZmRBOHC, were decreased in ZmWRKY29-OE lines following F. graminearum challenge. ZmWRKY29 directly binds to the W-boxes in the promoters of ZmRBOHA and ZmRBOHC to repress their transcription. Moreover, mutation of ZmRBOHC similarly led to increased susceptibility and diminished ROS accumulation, confirming that ZmWRKY29-targeted ZmRBOHC is required for ROS production and GSR resistance. Thus, ZmWRKY29 acts as a susceptibility factor, repressing GSR resistance possibly by inhibiting ZmRBOHC-mediated ROS production. This highlights a pathogen strategy of exploiting host transcriptional machinery to suppress ROS defences and facilitate infection.

A New Breeding Technique for F1 Hybrid Production From Self‐Incompatible Species

Fri, 06 Mar 2026 20:32:26 -0800

Plant Biotechnology Journal, EarlyView.

In Vivo Maternal Haploid Induction by Disrupting KOKOPELLI in Medicago truncatula

Thu, 05 Mar 2026 20:31:44 -0800

Plant Biotechnology Journal, EarlyView.