biolover

why whitefly is big problem for food security?

2017-01-03T03:24:00.004+02:00

The draft genome of whitefly Bemisia tabaci MEAM1, a global crop pest, provides novel insights into virus transmission, host adaptation, and insecticide resistance

AbstractBackground

The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is among the 100 worst invasive species in the world. As one of the most important crop pests and virus vectors, B. tabaci causes substantial crop losses and poses a serious threat to global food security.

Results

We report the 615-Mb high-quality genome sequence of B. tabaci Middle East-Asia Minor 1 (MEAM1), the first genome sequence in the Aleyrodidae family, which contains 15,664 protein-coding genes. The B. tabaci genome is highly divergent from other sequenced hemipteran genomes, sharing no detectable synteny. A number of known detoxification gene families, including cytochrome P450s and UDP-glucuronosyltransferases, are significantly expanded in B. tabaci. Other expanded gene families, including cathepsins, large clusters of tandemly duplicated B. tabaci-specific genes, and phosphatidylethanolamine-binding proteins (PEBPs), were found to be associated with virus acquisition and transmission and/or insecticide resistance, likely contributing to the global invasiveness and efficient virus transmission capacity of B. tabaci. The presence of 142 horizontally transferred genes from bacteria or fungi in the B. tabaci genome, including genes encoding hopanoid/sterol synthesis and xenobiotic detoxification enzymes that are not present in other insects, offers novel insights into the unique biological adaptations of this insect such as polyphagy and insecticide resistance. Interestingly, two adjacent bacterial pantothenate biosynthesis genes, panB and panC, have been co-transferred into B. tabaci and fused into a single gene that has acquired introns during its evolution.

Conclusions

The B. tabaci genome contains numerous genetic novelties, including expansions in gene families associated with insecticide resistance, detoxification and virus transmission, as well as numerous horizontally transferred genes from bacteria and fungi. We believe these novelties likely have shaped B. tabaci as a highly invasive polyphagous crop pest and efficient vector of plant viruses. The genome serves as a reference for resolving the B. tabaci cryptic species complex, understanding fundamental biological novelties, and providing valuable genetic information to assist the development of novel strategies for controlling whiteflies and the viruses they transmit.

原文地址：http://bmcbiol.biomedcentral.com/articles/10.1186/s12915-016-0321-y

What is non-host resistance?

2017-01-03T03:23:00.001+02:00

Nonhost resistance, a resistance of plant species against all non-adapted pathogens, is considered the most durable and efficient immune system of plants but yet remains elusive. The underlying mechanism of nonhost resistance has been investigated at multiple levels of plant defense for several decades. In this review, we have comprehensively surveyed the latest literature on nonhost resistance in terms of pre-invasion, metabolic defense, pattern-triggered immunity, effector-triggered immunity, defense signaling, and possible application in crop protection. Overall, we summarize the current understanding of nonhost resistance mechanisms. Pre- and post-invasion is not much deviated from the knowledge on host resistance except for a few specific cases. Further insights on the roles of the pattern recognition receptor gene family, multiple interactions between effectors from non-adapted pathogen and plant factors, and plant secondary metabolites in host range determination could expand our knowledge on nonhost resistance and provide efficient tools for the future crop protection using combinational biotechnology approaches.

Link:
http://apsjournals.apsnet.org/doi/abs/10.1094/MPMI-10-16-0213-CR?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed&

Essentials of Tritium Planigraphy

2016-11-05T17:06:00.000+02:00

The method is based on labeling organic compounds, including peptides and proteins, by bombarding the target (usually prepared by spray freezing the protein solution on the reactor wall chilled with liquid nitrogen) in a vacuum chamber with a beam of “hot” tritium atoms (generated through catalytic dissociation of molecular tritium at the surface of a tungsten filament heated to 2,000 K) (1). The resulting preparations are labeled to high specific activity and retain their structure and bioactivity (2、3). Labeling takes place by single collisions of tritium atoms with the target, and the intramolecular label distribution among amino acid residues is governed by their steric accessibility in the macromolecule (4). This crucial point has been verified with a quite broad range of objects (5) including complex supramolecular structures such as viruses (6、7) and ribosomes (8).

1、Shishkov A V, Filatov E S, Simonov E F, Gol’danskii V I, Nesmejanov A N. Dokl Akad Nauk SSSR.1976;228:1237–1239. [PubMed]

2、Ulmasov Ch A, Nesterova M V, Poletaev A I, Severin E S. Biochemistry (Moskow) 1981;46:1609–1612.

3、Yusupov M M, Spirin A S. Methods Enzymol. 1988;164:426–439. [PubMed]

4、Gol’danskii V I, Rumyantsev Yu M, Shishkov A V, Baratova L A, Belyanova L P. Mol Biol.1982;16:528–534.

5、Shishkov A V, Baratova L A. Russian Chem Rev. 1994;9:781–796.

6、Gol’danskii V I, Kashirin I A, Shishkov A V, Baratova L A, Grebenshchikov N I. J Mol Biol.1988;201:567–574. [PubMed]

7、Baratova L A, Grebenshchikov N I, Dobrov E N, Gedrovich A V, Kashirin I A, Shishkov A V, Efimov A V, Jarvekulg L, Radavsky Yu L, Saarma M. Virology. 1992;188:175–180. [PubMed]

8、Agafonov D E, Kolb V A, Spirin A S. Proc Natl Acad Sci USA. 1997;94:12892–12897.[PMC free article] [PubMed]

Fear of Fungi.

2016-11-05T16:44:00.003+02:00

Research pubished by Matthew Fisher and colleges indicates that more fungi have been emerged as infectious diseases, and are threatening diversity of ecosystems and agricultural productivity.

more detail can be found here:
http://fungalgenomes.org/blog/2012/04/fear-of-fungi/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+fungalcompgenomics+%28The+Hyphal+Tip%29

Figures from http://www.nature.com/nature/journal/v484/n7393/full/nature10947.html

植物抵御DNA病毒体系

2016-11-05T13:43:00.002+02:00

中国科学院遗传与发育生物学研究所利用新近在细菌中发现的适应性免疫系统特异识别病毒和外源DNA特性，将该成果引入植物，在植物中建立一套DNA病毒防御体系。

双生病毒是存在于植物中惟一一类具有孪生颗粒形态的单链DNA病毒，也是目前已知的最大单链DNA病毒家族，该病毒在单子叶和双子叶植物中具有广泛的宿主。目前已报道双生病毒能够感染玉米、棉花、番茄、木薯、甜菜等重要农作物，对农业生产危害极大。传统抗病机理的研究主要基于对病毒基因功能的分析及宿主病毒互作机理的解析，但目前在育种中的应用还比较有限。

中科院遗传与发育生物学研究所此次以甜菜严重曲顶病毒为模式病毒，通过实验证明：向植物中引入高效的适应性免疫系统，能有效地抑制甜菜严重曲顶病毒在寄主植物中的积累。此外，靶位点的突变分析表明该系统能特异性切割病毒DNA，利用此方法培育抗病毒植物，不必基于病毒基因功能的深入了解，简单易行，通用性强。因此，该研究对培育抗DNA病毒作物具有指导意义。

来源：北京日报

植物基因沉默抵抗双生病毒新机制

2016-11-05T13:40:00.001+02:00

植物转录后基因沉默(PTGS)和转录水平基因沉默(TGS)是其抵抗病毒以及其它外源基因的入侵的一套基于核酸的免疫系统。该系统能够监测、发现并及时清除病毒或外源基因的表达产物，产生对病毒等多种病原的抗性。近几年来，生物体如何在利用该机制抵抗病毒等病原入侵的同时，保持内源基因表达的稳定性是一个热点科学问题。

　　在最近20年内，由烟粉虱传播的双生病毒(Geminivirus)引起的病害已经从由局部发生衍变成为最重要的全球性植物病害之一，严重危害玉米、小麦、棉花、木薯、番茄等重要作物和观赏植物。例如仅木薯花叶病毒病一项，每年在非洲撒哈拉地区造成的经济损失就高达12-23亿美元之巨。由于缺乏有效抗病基因及种质资源，目前对双生病毒病害尚无环保高效的防治方法，仍主要依赖通过对介体昆虫的化学防治来实现病毒的预防与控制。中国科学院微生物研究所叶健青年研究组于2014年双生病毒与寄主植物、传毒介体昆虫烟粉虱三者互作取得重要进展的基础上（Li et al., Plant Cell 2014），同美国洛克菲勒大学蔡南海教授实验室合作，从植物对木薯花叶病毒的感病基因入手，在植物如何抵御双生病毒感染和病毒与植物基因沉默互作研究中，又鉴定了两类植物对木薯花叶病毒的易感基因，揭示了高等植物中保守的抵抗双生病毒病害的新机制，相关的工作已经发表在PLoS Pathogens 和Scientific Reports 上。这两类双生病毒的植物感病基因的发现，为发展广谱高效的植物抗双生病毒病害策略奠定了理论基础，并为通过基因组编辑技术获得增强作物抗病性提供了有效的分子靶标。

　　该团队研究人员利用遗传学、细胞学、分子生物学和病毒学等研究手段，首次发现叶型发育干细胞决定因子AS2是双生病毒易感基因，并且在负调控植物细胞质PTGS中发挥重要功能。他们发现AS2参与了植物细胞质mRNA decapping途径，抑制PTGS和植物对双生病毒的抗性。植物内源基因转录具有发生PTGS的潜在的风险，细胞质mRNA decapping途径在真核生物中非常保守，是重要的RNA降解途径，具有抑制PTGS的功能。而双生病毒通过促进AS2转录激活、AS2核质穿梭和增强decapping等策略，抑制植物PTGS的发生，增强其致病性。研究成果为发展高效防治双生病毒病害提供了新的靶点（PLoS Pathogens 2015, 11:e1005196），叶健为该文的第一作者和共同通讯作者，微生物所方荣祥研究员、叶健课题组的孙艳伟、赵平芝为共同作者。

　　除PTGS外，TGS也对双生病毒抗性起到重要作用。该团队研究人员发现本生烟草(Nicotiana benthamiana)组蛋白甲基转移酶NbKYP和DNA甲基转移酶NbCMT3是TGS途径的重要因子，通过对双生病毒基因组进行甲基化修饰，限制病毒复制和转录等事件的发生。在NbKYP低表达的本生烟草中，植物和双生病毒基因组的CG和CHG甲基化均大幅度的降低，揭示了NbKYP在TGS中的新特点。研究发现本生烟草也存在负调控TGS的机制，而木薯花叶病毒可以通过激活负调控因子NbRAV2抑制NbKYP转录，从而抑制了本生烟草TGS的发生，进而促进了病毒的复制。相关论文已经被Scientific Reports 接收，叶健为该文的通讯作者，叶健课题组的孙艳伟和马永焕为共同第一作者，姚香梅为共同作者。

　　这两项研究工作得到了中国科学院战略性先导科技专项（B类）-“作物病虫害的导向性防控项目（XDB11040300）”、国家自然基金委优秀青年项目（31522046）和植物基因组学国家重点实验室经费的资助。

病毒复制复合体与磷脂酰乙醇胺

2016-11-05T13:38:00.002+02:00

Plants, animals, and humans are threatened by positive-stranded RNA viruses, which are one of the major groups of intracellular pathogens. To support robust virus replication, these viruses subvert intracellular membranes and co-opt host proteins into virus-induced replication compartments. Tomato bushy stunt virus (TBSV) is a model virus used in yeast to dissect the roles of lipids and proteins in virus replication. In this work, the authors show that one of the two TBSV replication proteins interacts with the guanosine triphosphate (GTP)-bound Rab5 small GTPase, which allows the virus to take advantage of phosphatidylethanolamine (PE)-rich endosomes to build viral replication compartments consisting of peroxisomes. Peak level of TBSV replication depends on the co-opted abundant PE-rich Rab5-positive membranes in plants, too.
威胁人类、动物和植物的正单链RNA病毒是一类重要的细胞内病原物。为保证自身的复制，病毒必须需要同寄主互作，利用病毒的寄主来形成病毒诱导的复制复合体。下面的文章结果表明Tomato bushy stunt virus 复制蛋白通过与寄主TRab5 小GTPase互作来利用寄主富集磷脂酰乙醇胺的内体来构建病毒复制复合体。

Abstract

Positive-strand RNA viruses build extensive membranous replication compartments to support replication and protect the virus from antiviral responses by the host. These viruses require host factors and various lipids to form viral replication complexes (VRCs). The VRCs built by Tomato bushy stunt virus (TBSV) are enriched with phosphatidylethanolamine (PE) through a previously unknown pathway. To unravel the mechanism of PE enrichment within the TBSV replication compartment, in this paper, the authors demonstrate that TBSV co-opts the guanosine triphosphate (GTP)-bound active form of the endosomal Rab5 small GTPase via direct interaction with the viral replication protein. Deletion of Rab5 orthologs in a yeast model host or expression of dominant negative mutants of plant Rab5 greatly decreases TBSV replication and prevents the redistribution of PE to the sites of viral replication. We also show that enrichment of PE in the viral replication compartment is assisted by actin filaments. Interestingly, the closely related Carnation Italian ringspot virus, which replicates on the boundary membrane of mitochondria, uses a similar strategy to the peroxisomal TBSV to hijack the Rab5-positive endosomes into the viral replication compartments. Altogether, usurping the GTP-Rab5–positive endosomes allows TBSV to build a PE-enriched viral replication compartment, which is needed to support peak-level replication. Thus, the Rab family of small GTPases includes critical host factors assisting VRC assembly and genesis of the viral replication compartment.

老文章新讨论-系统性坏死与过敏性坏死（HR）

2016-11-05T12:03:00.002+02:00

Komatsu等2010年在MPMI上面发表了题为Viral-Induced Systemic Necrosis in Plants Involves Both Programmed Cell Death and the Inhibition of Viral Multiplication, Which Are Regulated by Independent Pathways 的文章，
文中在系统性坏死植物中发现类似于过敏性坏死反应的一些特性，例如PR1a, SGT1，RAR1等基因表达及其作用。但最终结论是系统性坏死和过敏性坏死反应都有PCD和抑制病毒繁殖的特点，但HR拥有自己特殊的途径。
怎么来看系统性坏死和过敏性坏死反应。

原文摘要：
Resistant plants respond rapidly to invading avirulent plant viruses by triggering a hypersensitive response (HR). An HR is accompanied by a restraint of virus multiplication and programmed cell death (PCD), both of which have been observed in systemic necrosis triggered by a successful viral infection. Here, we analyzed signaling pathways underlying the HR in resistance genotype plants and those leading to systemic necrosis. We show that systemic necrosis in Nicotiana benthamiana, induced by Plantago asiatica mosaic virus (PlAMV) infection, was associated with PCD, biochemical features, and gene expression patterns that are characteristic of HR. The induction of necrosis caused by PlAMV infection was dependent on SGT1, RAR1, and the downstream mitogen-activated protein kinase (MAPK) cascade involving MAPKKKα and MEK2. However, although SGT1 and RAR1 silencing led to an increased accumulation of PlAMV, silencing of the MAPKKKα-MEK2 cascade did not. This observation indicates that viral multiplication is partly restrained even in systemic necrosis induced by viral infection, and that this restraint requires SGT1 and RAR1 but not the MAPKKKα-MEK2 cascade. Similarly, although both SGT1 and MAPKKKα were essential for the Rx-mediated HR to Potato virus X (PVX), SGT1 but not MAPKKKα was involved in the restraint of PVX multiplication. These results suggest that systemic necrosis and HR consist of PCD and a restraint of virus multiplication, and that the latter is induced through unknown pathways independent from the former.

Potato virus disease is really a big problem affecting potato production

2016-04-27T07:01:00.000+03:00

I looked some potato production fields yesterday, It seems that potato virus diseases indeed is a big problem. In some field, 90% of potato plant display virus-like symptom, most of them are mosaic. In some field , which were grown in green house, and removed the cover recently, the potato grows much better. Discussed with the farmers, the yield difference is up to 40%. A big difference!

CRISPR/Cas9 and Targeted Genome Editing: A New Era in Molecular Biology

2016-04-26T08:44:00.003+03:00

the CRISPR/Cas9 is a still somehow new to many of us, but it has been widely used since its first reported. It has been applied in many organisms including animals and plant. It also has the potential application in human disease.
It is really a fantastic discover!

Another shocking news for today, a postdoc died....

2014-03-14T15:04:00.001+02:00

Heard from my college, a postdoc was died last night in the building few hundreds meters away from mine.....
Until now it said it was related chemical, further information will come late...

I thought bomb attack is far from me, it seems not

2014-03-14T15:02:00.001+02:00

Just saw the news police arrested two people who planned to bomb attach the university.....

what's wrong with the world.

http://www.helsinkitimes.fi/finland/finland-news/domestic/9811-iltalehti-two-suspected-of-planning-a-bomb-attack-on-university-of-helsinki.html

治疗hiv新方法初次尝试

2014-03-07T18:56:00.001+02:00

首次通过编辑基因来处理hiv。

http://dx.doi.org/10.1038/nature.2014.14813

Call for copyright to move with the times－from research professional

2014-03-06T21:18:00.003+02:00

Call for copyright to move with the times

Academics want EU-wide permission to mine data

Special provisions are urgently needed to stop copyright laws from hampering research activities, according to universities, libraries and funders.

Academic institutions say their staff must be free to carry out text and data mining, which involve using computer programmes to trawl through and analyse vast amounts of information from scientific papers. Such use is restricted by EU copyright legislation, but that could be about to change as the European Commission has launched a consultation to review the laws.

In consultation responses seen by Research Europe, several groups are calling for EU-wide exemptions to copyright for research purposes, on the basis that the regulations are stifling scientific and economic competitiveness. “We are very worried about this,” says Kurt Deketelaere, secretary-general of the League of European Research Universities.

Interest in computer-based mining techniques is growing among researchers as the volume of papers accessible online increases and better analytical technologies become available. But the respondents say that EU copyright laws have not kept up with this trend.

“Activities such as text and data mining are being hindered by a copyright framework that was not designed for the digital environment,” says the Association of European Research Libraries. “It is imperative that the framework is adapted to ensure that European innovation is competitive.”

The EU copyright directive allows member states to choose whether or not to implement a limit on non-commercial scientific research, meaning that laws vary widely. Many scientific publishers block the use of computer programmes for mining but grant permission on a case-by-case basis to academics who subscribe to their journals.

“What we really want is a clear, indisputable exemption for academic research, so there can be no discussion in the 28 member states or among different commercial players,” says Deketelaere.

“We think that content that people have already paid for should be free to read by computers as well as to read by eye,” says David Carr, a policy adviser at the Wellcome Trust, a UK-based medical research charity. The trust estimates that, under a licensing approach, a researcher wishing to mine 8,000 articles could spend up to 60 per cent of a working year—at a cost of €22,000—gaining permission from the articles’ publishers. “If researchers have to negotiate access to content on a journal-by-journal basis, it rapidly becomes unworkable,” says Carr.

Scientific groups are concerned that the Commission may only be considering a revision of the licensing procedures for text and data mining, rather than a fundamental law change. However, Pierre Delsaux, deputy director-general at the Directorate-General for Internal Market and Services, which oversees the consultation, refutes the idea that the outcome of the review is predetermined. “We have held the consultation to have a real debate,” he says, adding that the ability of the creative industries, including publishing, to remain economically viable must be taken into account.

In response to researchers’ demands, some publishers have started to make concessions. In January, Elsevier announced plans to allow text mining by subscribers on its ScienceDirect database. But the system contains restrictions on the amount of text that can be published, which some researchers object to.

The consultation was due to close on 5 March and the Commission intends to produce a white paper based on the outcome, after which it will begin discussions on future legislation. “Whatever we propose will be very difficult to negotiate,” says Delsaux. “There are a lot of interests at stake and it will be a lengthy process.”

But Deketelaere warns that if no exemption is made for academic research, this will be “the beginning of the war” between publishers and universities. “Everything up until now on open access is peanuts compared with this,” he says.

- See more at: http://www.researchprofessional.com/0/rr/news/europe/universities/2014/3/call-for-copyright-to-move-with-the-times.html#sthash.VggPj4qA.dpuf

Call for copyright to move with the times－from research professional

2014-03-06T21:18:00.002+02:00

Call for copyright to move with the times

Academics want EU-wide permission to mine data

Special provisions are urgently needed to stop copyright laws from hampering research activities, according to universities, libraries and funders.

“What we really want is a clear, indisputable exemption for academic research, so there can be no discussion in the 28 member states or among different commercial players,” says Deketelaere.

- See more at: http://www.researchprofessional.com/0/rr/news/europe/universities/2014/3/call-for-copyright-to-move-with-the-times.html#sthash.VggPj4qA.dpuf

Coffee could help memory

2014-03-05T20:52:00.001+02:00

Just hears the news from voa,they said the research showed coffee could increase the ability to memorize, but also increase nervous .

giant virus is coming back

2014-03-04T15:18:00.001+02:00

latest news from nature.

scientist researchers have found a giant virus from 30000 years old ice, and this giant virus still infectious.
learn more: find more information here

Nature:

doi:10.1038/nature.2014.14801

climate change-what can we do?

2014-03-02T11:39:00.001+02:00

what could we do with the climate change ? could we stop it ? i am not in this area. but it is hot topic nowadays.
for me i could feel the environment around me is changing, comparing with the memo ten years ago..
in my home town, i have not seen snowing for many years, the rain is also less and less, especially recent few years.
few days ago, have read one paper from nature climate, the authors have utilized earth system model to see the effects of different method for climate changing. it seems like the methods have little effect on climate change if i did't understood wrongly.
i am thinking whether we could stop the climate changing or we just could slow down the changing process?

the most important thing, we should try our best to have better living environment, good water, air.....

fake papers-more are found

2014-03-02T11:21:00.001+02:00

it is sad to read this news for all scientist, but we could not avoid it and have to face the problem. what is the reason for producing these non-sense papers.

According to recent news from nature, there're about 120 are found as fake paper, and most of them from china. most of these paper are generalized by a software called scigen.

there are several things we should think about,
1, why some scientist willing to produce such fake paper?
2, how these fake paper pass the examination of peer reviews?
3, what could we do to improve such problem?

we should re-think the publishing systems. not only you, me, but also the government, publishers, and reviewers....

original news could be found in the following link:
http://www.nature.com/news/publishers-withdraw-more-than-120-gibberish-papers-1.14763

Field Virology 6th available

2014-02-27T12:29:00.001+02:00

Fields Virology is the authoritative reference book for virology, providing definitive coverage of all aspects of virology, including thorough coverage of virus biology as well as replication and medical aspects of specific virus families. With the regular outbreaks of influenza, noroviruses as well as other emerging and re-emerging viruses it is essential to have the most up-to-date information available.

With this Sixth Edition, all chapters have been completely updated, an important new emphasis has been placed on virus discovery and emerging viruses. Viruses associated with cancer, including the new human polyomaviruses, are highlighted in this Sixth Edition and new chapters have been added on circoviruses and mimiviruses.

While the main focus of this edition continues to be on viruses, information on prions and the infectious spongiform encephalopathies are also included.

FEATURES• 2-volume set
• Full color throughout with over 1,000 illustrations in total and most chapters provide key figures for use as lecture slides
• Online companion website with fully searchable text, all references linked to PubMed and additional material not found in the print for access to content anytime
• New coverage of emerging and viruses, including those causing influenza and HIV
• Updated coverage of viruses and cancer
• Coverage includes virus structure, virus entry, replication, and assembly, virus-host cell interactions, host immune responses and vaccines, antiviral therapeutics, virus evolution and immunization
• Thorough coverage of all viruses of medical importance, including both basic science and clinical features
• New chapters on circoviruses and mimiviruses and a new section on Chikungunya virus have been added
• Important advances in antivirals, including new HCV protease inhibitors and HIV integrate inhibitors

http://www.lww.com/webapp/wcs/stores/servlet/product_Fields-Virology_11851_-1_9012053_Prod-9781451105636?cm_sp=PE-MED-InfectiousDiseases-_-Banner-InfectiousDiseases-_-Left-NoPromo-FieldsVirology-NewEdition

plant factory-producing medicine

2014-02-26T20:47:00.000+02:00

制造蛾信息素的植物工厂

蛾类通过信息素的交流来寻找配偶，人工合成的信息素通常用来监控或者干扰害虫的信息素交流。该研究以本生烟作为工厂通过瞬时表达最多四个编码基因来连续合成途径，我们生产出两种蛾类特异的多组分性信息素。来自经过遗传修饰植物的脂肪醇片段加速了属于小巢蛾Yponomeuta evonymella 和Y. padella性信息素的模拟过程。这些混合物非常有效和特异的诱捕雄性蛾，这说明符合常规的性信息素。我们的长期目标是在遗传修饰的植物中设计量身定做的任何蛾类信息素。这种半合成制备性信息素是一个生产中等至大规模生产高质量低污染的非常新颖和非常划算的方式

Moths depend on pheromone communication for mate finding and synthetic pheromones are used for monitoring or disruption of pheromone communication in pest insects. Here we produce moth sex pheromone, using Nicotiana benthamiana as a plant factory, by transient expression of up to four genes coding for consecutive biosynthetic steps. We specifically produce multicomponent sex pheromones for two species. The fatty alcohol fractions from the genetically modified plants are acetylated to mimic the respective sex pheromones of the small ermine moths Yponomeuta evonymella and Y. padella. These mixtures are very efficient and specific for trapping of male moths, matching the activity of conventionally produced pheromones. Our long-term vision is to design tailor-made production of any moth pheromone component in genetically modified plants. Such semisynthetic preparation of sex pheromones is a novel and cost-effective way of producing moderate to large quantities of pheromones with high purity and a minimum of hazardous waste.

http://www.nature.com/ncomms/2014/140225/ncomms4353/full/ncomms4353.html

Fish skeleton

2014-02-23T08:27:00.001+02:00

Novelli meal,

After 10 minutes

Fifth edition Plant Virology

2014-02-21T09:09:00.001+02:00

The seminal text Plant Virology is now in its fifth edition. It has been 10 years since the publication of the fourth edition, during which there has been an explosion of conceptual and factual advances.

The fifth edition of Plant Virology updates and revises many details of the previous edition while retaining the important earlier results that constitute the field's conceptual foundation. Revamped art, along with fully updated references and increased focus on molecular biology, transgenic resistance, aphid transmission, and new, cutting-edge topics, bring the volume up to date and maintain its value as an essential reference for researchers and students in the field.

Thumbnail sketches of each genera and family groups
Genome maps of all genera for which they are known
Genetic engineered resistance strategies for virus disease control
Latest understanding of virus interactions with plants, including gene silencing
Interactions between viruses and insect, fungal, and nematode vectors
Contains over 300 full-color illustration

Address:

http://www.sciencedirect.com/science/book/9780123848710

nice lily

2014-02-19T20:00:00.001+02:00

Ice cream

2014-02-19T19:59:00.001+02:00