SRBSDV编码P6蛋白调控水稻乙烯信号转导引诱传毒昆虫的分子机理

Over past few years, Southern rice black-streaked dwarf virus (SRBSDV) has caused serious loss in rice production. Our previous study found that the effector P6 of SRBSDV could activate the ethylene signaling of rice plants to increase the attractiveness to the vector white-backed planthopper, which facilitates transmission and spread of the virus, and a key protein in rice ethylene signal transduction, OsEBF1, was identified interacting with the effector P6 by immunoprecipitation. In this project, further studies via molecular biology, biochemistry, cell biology and other research methods will carried out to elucidate the interaction of virus effector and host factor, uncover the interaction mechanism of virus effector and host factor, resolve the regulation mechanism of P6 via OsEBF1 on ethylene signal transduction in rice, verify the biological phenomenon by generating overexpression and gene editing mutants of OsEBF1, and clarify the mechanism of ethylene pathway mediating SRBSDV improved vector attractiveness of rice plants. Finally, our results will elucidate the molecular mechanism of SRBSDV modulated ethylene signal transduction in rice to promote the virus transmission, and the results will provide a new theoretical basis for the prevention and control of the spread of SRBSDV.

近年来南方水稻黑条矮缩病毒(Southern rice black-streaked dwarf virus，SRBSDV)对我国及周边国家的水稻生产造成了严重危害。我们前期研究发现，SRBSDV编码的P6蛋白通过激活水稻乙烯信号来提高对介体白背飞虱的引诱能力，从而促进病毒传播扩散，且通过免疫共沉淀发现P6能与水稻乙烯信号转导中的关键蛋白OsEBF1互作。本项目拟对SRBSDV P6效应蛋白-寄主因子的分子互作开展深入研究：通过分子生物学、生物化学、细胞生物学等研究手段剖析P6效应蛋白与寄主因子OsEBF1的互作机制，解析P6对水稻乙烯信号转导的调控机理；对互作因子OsEBF1的超表达和基因编辑突变体进行生物学验证，明确乙烯信号介导SRBSDV提高水稻引诱白背飞虱的机制，最终阐明SRBSDV调控水稻乙烯信号转导促进介体传毒的分子机理。研究结果将为防控SRBSDV的流行提供新的理论依据。

南方水稻黑条矮缩病毒（Southern rice black-streaked dwarf virus，SRBSDV）严重为害水稻生产，破解其流行成灾机制是病害科学防控的基础。前期研究发现SRBSDV在不同侵染阶段差异调节白背飞虱和水稻的相互作用，通过感病植株对白背飞虱的“推-拉”效应促进病毒传播。本项目通过遗传学和昆虫行为学的手段发现水稻乙烯信号介导了SRBSDV侵染和介体传播，并通过分子生物学、细胞生物学等研究手段发现SRBSDV编码的P6蛋白是调控水稻乙烯信号的效应蛋白。在病毒侵染的前期，P6蛋白主要定位在细胞质，通过与水稻乙烯信号负调控因子OsRTH2特异性互作来增强乙烯信号，从而促进病毒的增殖。随着病程的进展，P6蛋白逐渐向细胞核内积累，与核内乙烯信号的关键转录因子OsEIL2特异性互作，通过破坏后者二聚体形成来抑制乙烯信号，从而增强水稻对白背飞虱的引诱能力。该研究揭示了南方水稻黑条矮缩病毒通过其编码的P6蛋白在侵染不同时期亚细胞定位的转变，双向调控水稻的乙烯信号，在病毒侵染进程中协调病毒增殖和介体传播。这一发现为我们理解植物-病毒-昆虫三界生物互作提供了新的认识，也为该重要病害的科学防控提供了新的理论依据。本项目在Molecular Plant和Plant Biotechnology Journal等期刊发表论文5篇，授权专利1项，培养学生5名。