Genomic Approaches to Unravel Virulence and Resistance Determinants of Vector-transmitted Viruses in Tomato

Pi：S.P.Dinesh-Kumar(加州大学戴维斯分校)Copis：Robert Gilbertson，Diane Ullman和Ilias Tagkopoulos(加州大学戴维斯分校)番茄是世界上第二大蔬菜作物。番茄生产受到两种毁灭性的昆虫传播病毒--番茄斑枯病病毒(TSWV)和番茄黄化卷叶病毒(TYLCV)的威胁。这些病毒的管理很困难，而且往往严重依赖于使用杀虫剂来控制媒介。杀虫控制往往无效，对人类健康和环境有负面影响，并可能导致选择抗药性形式的媒介。在番茄中，TYLCV的Ty1基因座和TSWV的SW5基因座是主要的遗传抗源，并已导入商品番茄品种。然而，对Ty1和SW5介导的抗性机制知之甚少。该项目将为了解植物抗性和昆虫传播病毒感染敏感性的机制的性质和相互作用提供新的见解。这些研究将深入了解在感染和/或宿主防御过程中，RNA(TSWV)和DNA(TYLCV)病毒针对的是相似还是不同的途径。然后，该项目将使用这些研究的结果来优化和验证一种名为miRNA诱导的基因沉默(MiGs)的新方法，该方法可用于评估番茄的基因功能。如果成功，该项目的结果可能会导致针对这些病毒的新一代抗病毒策略。该项目还将每年为萨克拉门托城市学院的本科生和戴维斯高中的高中生提供为期10周的培训计划。从野生番茄近缘导入栽培番茄的SW5和Ty1基因座分别介导的遗传抗性分别提供了对TSWV和TYLCV的最佳保护源。该项目的研究人员假设，SW5和Ty1介导的TSWV和TYLCV的识别触发了早期和可识别的转录变化，涉及共同和特定的免疫信号网络。此外，这些病毒在感病番茄上的感染会诱导转录变化，从而促进病毒的毒力。为了深入了解转录变化，研究人员将使用RNAseq方法来鉴定番茄在TSWV和TYLCV抗性和感病反应过程中的差异表达转录本。将使用计算方法分析RNAseq数据，以确定在TSWV和TYLCV抗性和易感相互作用过程中差异调控的关键共同和特定基因。该项目将针对已知的候选基因，优化和验证用于转基因番茄基因功能研究的MiGs方法。优化的MIGS方法将用于评估所选差异表达基因在番茄TYLCV和TSWV抗性和感病互作过程中的功能。该项目的结果可能会为设计新一代策略提供见解，不仅控制TYLCV和TSWV，而且还控制其他重要的植物病原体。所有数据和生物资源都将向公众开放。所有RNASEQ数据将通过GEO存放并可用。所有MIG载体和候选靶基因构建物将根据要求和通过Addgene(https://www.addgene.org/)和abrc(http://www.biosci.ohio-state.edu/~plantbio/Facilities/abrc/abrchome.htm).)获得转基因番茄品系的种子将通过加州大学戴维斯分校的番茄遗传资源中心(http://tgrc.ucdavis.edu/).)获得

PI: S.P. Dinesh-Kumar (University of California-Davis)CoPIs: Robert Gilbertson, Diane Ullman, and Ilias Tagkopoulos (University of California-Davis)Tomato is the second most important vegetable crop in the world. Tomato production in the US and worldwide is threatened by two devastating insect-transmitted viruses - tomato spotted wilt virus (TSWV) and tomato yellow leaf curl virus (TYLCV). Management of these viruses is difficult and often relies heavily on the use of insecticides to control the vectors. Insecticidal control is often ineffective, has negative human health and environmental effects, and can lead to selection of insecticide-resistant forms of the vectors. In tomato, the Ty1 locus for TYLCV and the Sw5 locus for TSWV are major genetic resistance sources, and both have been introgressed into commercial tomato varieties. However, very little is known about the mechanisms involved in Ty1- and Sw5-mediated resistance. This project will provide new insights into the nature of and interplay between mechanisms of plant resistance and susceptibility to infection by insect-transmitted viruses. These studies will provide insights into whether similar or different pathways are targeted by RNA (TSWV) versus DNA (TYLCV) viruses during infection and/or host defense. The project will then use the results from these studies to optimize and validate a new approach called miRNA-induced gene silencing (MIGS) that can be used to assess gene function in tomato. If successful, the outcomes of this project will likely lead to a new generation of antiviral strategies against these viruses. The project will also provide a 10-week training program every year for undergraduate students from Sacramento City College and high school students from Davis Senior High School.The genetic resistance mediated by Sw5 and Ty1 loci introgressed from wild tomato relatives into cultivated tomato provides the best source of protection against TSWV and TYLCV, respectively. The investigators of this project hypothesize that Sw5- and Ty1-mediated recognition of TSWV and TYLCV trigger early and discernable transcriptional changes that involve common and specific immune signaling networks. In addition, infection of these viruses on susceptible tomato genotypes induces transcriptional changes that promote virus virulence. To gain insights into the transcriptional changes, the investigators will use RNAseq approach to identify differentially expressed transcripts during TSWV and TYLCV resistance and susceptible responses in tomato. Computational methods will be used to analyze RNASeq data to identify key common and specific genes that are differentially regulated during TSWV and TYLCV resistance and susceptible interaction. The project will optimize and validate the MIGS approach for gene function studies in transgenic tomato by targeting known candidate genes. The optimized MIGS approach will be used to evaluate function of selected differentially expressed genes during TYLCV and TSWV resistance and susceptible interactions in tomato. Results from the project will likely provide insights into designing new generation of strategies to control not only TYLCV and TSWV but also other important plant pathogens. All data and biological resources will be accessible to the public. All RNAseq data will be deposited and available through GEO. All MIGS vector and candidate target gene constructs will be available upon request and through Addgene (https://www.addgene.org/) and ABRC (http://www.biosci.ohio-state.edu/~plantbio/Facilities/abrc/abrchome.htm). Seeds from transgenic tomato lines will be available through the Tomato Genetics Resource Center at UC Davis (http://tgrc.ucdavis.edu/).