抗病基因Piz-t介导的水稻响应稻瘟病菌侵染的泛素化蛋白组学研究

Rice blast, caused by Magnaporthe oryzae is one of the most serious disease of rice production worldwide. Controlling this disease has been a hot research spot to date. Post-translational modifications, such as phosphorylation, ubiquitination and acetylation play an important role in plant defense against pathogens. Furthermore, understanding of the epigenetic mediated plant resistance, signals and networks and identification of the extent and nature of epigenomic changes induced by pathogens remain to be elucidated. To explore the molecular mechanisms involved in Piz-t mediated rice compatibility and incompatibility against rice blast, we will analyze the changes of rice ubiquitome on resistant and susceptible response at various time points after rice blast inoculation by using proteomics、biochemistry and molecular biology approaches. This study will provide new sights into the regulatory mechanism for ubiquitinated proteins involved in disease resistance signal transduction pathways and this also is the first attempt to identify rice ubiquitome changes induced by rice blast. Understanding the mechanism of plant ubiquitination regulating resistance to pathogens will provide a new strategy for rice disease control.

稻瘟菌（Magnaporthe oryzae）引起的稻瘟病是水稻生产上最重要的病害之一，对其防治一直是研究的重点。阐明磷酸化、泛素化、乙酰化等蛋白翻译后修饰在植物抗病防卫反应的作用及调控机制是植物病理学领域的前沿课题，系统研究蛋白翻译后修饰对于深入认识植物抗病反应的分子机制具有重要意义。本项目以蛋白泛素化修饰在水稻抗稻瘟病反应中的作用及其机制为切入点，综合运用蛋白质组学、生物化学、分子生物学技术，从多个层面分析比较抗病基因Piz-t介导的水稻-稻瘟病菌抗、感病互作中的泛素化蛋白变化动态，为解析泛素化蛋白参与水稻抗病反应的分子调控机制提供依据。研究获得的新抗病调控基因，将为转基因创制水稻等农作物抗病新种质、新品种提供基因资源。

泛素蛋白酶体修饰是生物体内最精细的调控体系之一，涉及对生物体生长发育以及适应环境的调控。研究表明植物中26S泛素蛋白酶体系，尤其是其中的E3泛素连接酶参与了各种抗病信号反应途径的调控。本项目采用蛋白质组学、生物化学、生物信息学的方法展开以下几方面的研究：对Piz-t介导的水稻-稻瘟病菌间亲和与非亲和互作中的泛素化修饰动态进行分析，并对候选基因OsMRE5的抗病功能、亚细胞定位、互作蛋白进行研究；对模式识别受体识别病原物模式分子chitin、flg22处理后的水稻泛素化修饰进行研究；对水稻受氨基寡糖素（COS）处理后的蛋白组进行鉴定；对水稻去泛素化酶OsUCH-L5的表达进行分析；对E3泛素连接酶U-box家族进行鉴定和表达分析，上述研究结果为下一步基因功能研究奠定基础。同时，在本项目的支持下，课题组共参加国际、国内学术会议4次；发表SCI论文7篇，授权专利7项。