水稻条纹花叶病毒和水稻瘤矮病毒在介体昆虫体内协生作用机制研究

Rice stripe mosaic virus (RSMV) and Rice gall dwarf virus (RGDV) which are transmitted by leafhopper vector Recilia dorsalis, in a persistent-propagative manner, cause severe rice damage in south China. We previously demonstrated that rice plants and R. dorsalis in nature are commonly coinfected with RSMV and RGDV, synergistic interactions occur in mixed infections of RSMV and RGDV in R. dorsalis, and these result in enhanced accumulation of RSMV. The two viruses accumulate and colocalize in membrane vesicles within midgut epithelium cells. We deduced that the synergism may be generated by direct interactions between the two viruses. Thus, the approaches including cell biology, protein interaction, transcriptome and RNA interference will be used to identify RGDV proteins that interact with RSMV proteins, screen vector components that are involved in the synergism, characterize the regulation of virus containing vesicle formation and function. The results will uncover the mechanism underlying this unique transmission mode involving synergism between RSMV and RGDV.

由介体电光叶蝉（Recilia dorsalis）以持久增殖型方式传播的水稻条纹花叶病毒（Rice stripe mosaic virus, RSMV）和水稻瘤矮病毒（Rice gall dwarf virus, RGDV）目前在我国南方稻区有蔓延暴发的趋势。前期研究发现RSMV和RGDV在田间普遍以复合侵染的形式存在，在复合侵染的电光叶蝉肠道上皮细胞中两个病毒共同包裹于膜状囊泡中，而且RGDV可以促进RSMV在介体中的增殖和扩散，推测二者在介体中可能通过直接互作产生协生关系。为此，本项目拟利用细胞生物学、蛋白互作、转录组学和RNA干扰等技术体系，鉴定RSMV和RGDV间直接互作的病毒蛋白，筛选参与调控二者协生关系的介体因子，揭示包裹RSMV和RGDV的膜状囊泡形成机制，阐明RSMV和RGDV采用协生关系经由介体昆虫有效传播的奇特机制。

介体电光叶蝉（Recilia dorsalis）以持久增殖型方式传播水稻条纹花叶病毒（RSMV）和水稻瘤矮病毒（RGDV），这两种病毒在田间常常复合侵染水稻和介体电光叶蝉，并在我国南方稻区逐渐蔓延和流行。本项目在前期揭示RGDV可以促进RSMV在介体中的增殖和扩散的基础上，推测这两种病毒的持续流行可能由它们在介体体内的这种协生关系导致的。因而利用细胞生物学、蛋白互作和RNA干扰等手段，对这两种病毒在介体体内的传播机制进行了深入研究。一方面解析了RGDV在介体体内垂直传播的机制和RSMV在介体体内的侵染循回机制，另一方面发现RSMV N蛋白可通过与RGDV Pns11蛋白的直接互作加快介体对病毒的获取及病毒在体内的扩散，同时发现介体更偏向取食RSMV侵染的水稻，更加有利于病毒在田间的传播。因此在介体昆虫体内RSMV和RGDV之间存在协生关系，有利于病毒病在田间的流行。.研究成果在Nature Communications、Frontiers in Microbiology和昆虫学报期刊发表3篇高质量论文，并在《知识就是力量》杂志发表以“植物病毒传播36计”为题的科普论文1篇。培养2名博士，4名硕士。研究成果为解析RSMV和RGDV在中国南方稻区持续蔓延的机制奠定了理论基础。