类受体蛋白激酶XRK1调控作物对疫霉菌基础抗性机制研究

植物细胞膜免疫受体通过识别病原菌保守模式分子激发的抗病反应是植物基础抗性的重要组成部分。申请人以我国大豆生产上主要病害的病原大豆疫霉为材料，以大豆疫霉与非寄主植物烟草的互作为研究系统，对非寄主识别疫霉菌模式分子XEG1的信号途径进行深入系统的研究，以期解析植物对疫霉菌基础抗性的分子机制。申请人前期通过对烟草中403个细胞膜类受体基因的分析，鉴定到植物识别XEG1的受体蛋白RXEG1。本项目拟进一步分析RXEG1下游一个参与免疫信号传递的关键类受体蛋白激酶XRK1的生物学功能。拟通过免疫共沉淀结合蛋白质谱的方法分析XRK1如何与RXEG1受体复合物相互作用、被修饰，并通过遗传学方法分析XRK1与XEG1信号传导机制和对疫霉菌抗性的关联性，从而揭示该类受体蛋白激酶调控XEG1免疫信号的作用模式，阐明XEG1激活植物先天免疫信号传导的作用机制，为改良作物抗病性提供资源和理论指导。

Membrane-localized immune receptors elicit plant basal resistance upon recognition of pathogen-associated molecular patterns (PAMPs). XEG1 is a PAMP secreted by Phytophthora pathogens that triggers defense in plants. Studies on plant recognition of XEG1 are essential for our understanding of the mechanisms underlying plant basal resistance. The receptor-like protein RXEG1 was recently identified that recognizes XEG1 and is essential for XEG1-triggered plant defense. However, how the recognition signal is transduced to initiate plant defense responses is not yet known. A high throughput screening of membrane-localized receptor-like genes results in the identification of the receptor-like kinase XRK1 that participates in XEG1-induced defense transduction. In this study, we will use co-immunoprecipitation, LC-MS/MS and genetic approaches to investigate the biological function of XRK1 as well as its interaction receptor complex, in order to understand how XRK1 regulates signal transduction upon recognition of XEG1, and how to initiate plant basal resistance against Phytophthora pathogens. This study will provide novel insights on plant innate immunity and will also be instrumental for developing plant durable disease resistance.