蛋白激发子EsxA诱导水稻抗病性机制

以激发子诱导抗性是植物病害防治的有效手段，揭示其作用机理是当前研究的重要任务。前期研究中发现一个早期分泌抗原靶6家族蛋白EsxA具有激发子活性，可诱导植物过敏反应、活性氧爆发及一系列水稻病程相关蛋白（PRs）基因上调表达，增强了水稻对稻瘟病及立枯病的抗性，极具应用潜力。但该EsxA诱导水稻抗病性的机制尚不明确。本研究拟建立EsxA-水稻互作体系，1）从转录及代谢层次确证EsxA诱导PRs基因上调表达及激素类物质积累，并激活水稻抗病信号转导链，增强水稻抗病性；2）鉴定水稻细胞中的EsxA受体蛋白，阐明EsxA与水稻细胞受体特异识别并结合、形成抗病信号、活化信号转导链、激活防卫基因表达，进一步调控激素代谢，进而增强植株抗病性的分子机制。预期研究结果/结论可丰富诱抗型激发子对植物病害防治的理论，为EsxA在诱抗剂类生物农药开发中的应用奠定基础。

Inducing plant resistance using elicitors is one of effective methods to control plant diseases, and explaining their mechanism of action are the primary tasks in current. In a previous study, a EsxA gene encoded earlier secreted antigen target 6 was found be an elicitor, that can produce positive hypersensitive response, reactive oxygen species burst, up-regulate pathogenesis-related proteins (PRs) gene expression and can induce plant resistance to rice blast and seedling blight, thus has a potential of application. However, the mechanism by which EsxA enhances rice diseases-resistance is unclear. In this study, an interacting system between EsxA and rice will be established, and (1) we will verify from the transcription and metabolic levels that EsxA induces PRs genes to up-regulate expression and regulates hormone accumulation in rice, then triggers signal transduction chains to enhance rice disease resistance ; (2) we will identify a EsxA-receptor protein in rice cell to illuminate the molecular mechanism of EsxA inducing plant disease-resistance, by which EsxA recognizes and binds to receptors distinctively, then disease resistance signals form and activates the signal transduction chains, triggers the expression of defense genes, thereby enhances rice disease resistance. The results/conclusions will contribute to enriching the theories of resistance-inducing elicitors controlling plant diseases and provide a basis for the application of EsxA on the development of resistance-inducing biological pesticides.