Dissectation of an EDM-2-Dependent Signaling Mechanism Mediating Resistance to Hyaloperonospora Parasitica in Arabidopsis

植物病害是造成农作物生产严重损失的原因。植物对病原微生物的抗性通常是由抗病基因介导的，抗病基因介导病原体的识别并触发防御反应。R基因活性水平的精确调节对其功能至关重要。然而，R基因调控的机制还不清楚。最近鉴定的EDM 2蛋白是控制R基因转录（mRNA合成）的新调节因子。使用酵母双杂交系统（检测蛋白质/蛋白质相互作用的体内测定）的筛选鉴定了与EDM 2物理相互作用的多种蛋白质。结合遗传学和生物化学方法，EDM 2及其互作伙伴在调节R基因活性和抗病性中的分子作用将被研究。EDM 2和它的推定的合作伙伴之间的物理相互作用将在未经处理的和防御激活的植物进行分析。将测试在编码EDM 2及其相互作用配偶体的基因中具有突变的植物系对R基因活性的影响。此外，将检查和表征这些蛋白质与R基因的调控DNA区域的结合。这些研究将增加我们对R基因调控机制细节的理解，并将提供植物免疫系统的几个新组件的详细表征。更广泛的影响：该项目的一个重要组成部分是主要来自少数群体的本科生的大力参与。该项目将与UC-Riverside植物细胞生物学中心正在进行的NSF-REU植物细胞生物学计划相联系。此外，该项目将为培养分子遗传学、基因组学和植物病理学领域的博士后学者和研究生提供一个出色的平台。这项研究的结果可能允许设计新的策略，通过操纵EDM 2及其互作因子的功能来提高作物的抗病性。

Plant diseases are the cause for dramatic losses in crop production. Resistance of plants to pathogenic microorganisms is often mediated by disease resistance (R) genes that mediate recognition of pathogens and trigger defense reactions. Accurate regulation of R gene activity levels is critical for their function. However, mechanisms of R gene regulation are not well understood. The recently identified EDM2 protein is a novel regulator that controls transcription (mRNA synthesis) of R genes. Screens using the yeast two-hybrid system (an in vivo assay detecting protein/protein interactions) identified multiple proteins that physically interact with EDM2. Combining genetic and biochemical methods molecular roles of EDM2 and its interaction partners in regulating R gene activity and disease resistance will be examined. Physical interactions between EDM2 and its putative partners will be analyzed in untreated and defense-activated plants. Plant lines with mutations in the genes encoding EDM2 and its interaction partners will be tested for effects on the activities of R genes. In addition, binding of these proteins to regulatory DNA regions of R genes will be examined and characterized. These studies will increase our understanding of mechanistic details of R gene regulation and will provide a detailed characterization of several novel components of the plant immune system. Broader impacts: An important component of this project is strong involvement of undergraduate students, mainly from minority groups. The project will be linked to the ongoing NSF-REU Plant Cell Biology program within the Center for Plant Cell Biology at UC-Riverside. In addition, the project will provide an outstanding platform for training of postdoctoral scholars and graduate students in the fields of molecular genetics, genomics and phytopathology. Results from this study are likely to allow the design of new strategies to improve disease resistance in crops by manipulating function of EDM2 and its interactors.