昆虫细胞自噬调控介体电光叶蝉传播水稻瘤矮病毒的机制

The rice gall dwarf disease caused by Rice gall dwarf virus (RGDV), is one of the important and insect-transmitted rice viral diseases in the South of China in recent years. RGDV is transmitted by leafhopper vector Recilia dorsalis, in a persistent-propagative manner. RGDV can be transmitted vertically from parents to offsprings in a transovarial manner. Previous field surveys and laboratory studies shows that RGDV infection has a deleterious effect on the growth and development of its leafhopper vectors. Thus, we deduced that RGDV infection modulates the population dynamic of its vectors in the field, which finally affecting the occurrence and epidemics of rice gall dwarf disease. In this proposal, we will use the methods including cultured insect vector cells, immunofluorescence technique and RNA interference (RNAi) to investigate the effects of viral infection on the functions of the cell autophagy in the cells, insects and field levels. We will also identify the effects of RGDV regulation cell autophagy on the growth and development in vector bodies. And the relationship between cell autophagy and population dynamic and viruliferous rate of R. dorsalis at over-wintering stage will be analysed using field surveys and laboratory detection. The results will lead us to identify the mechanism of insect cell autophagy regulates the transmission of Rice gall dwarf virus by R. dorsalis, and which would explore the disease epidemics patterns and provide theory basis for designing efficient control disease strategies in future.

由水稻瘤矮病毒（Rice gall dwarf virus, RGDV）引起的水稻瘤矮病是我国南方稻区重要的虫传病毒病害，目前在我国南方稻区有蔓延暴发的趋势。RGDV主要由电光叶蝉（Recilia dorsalis）以持久增殖型方式并经卵传播。田间调查及实验室研究表明RGDV侵染对介体电光叶蝉的生长发育存在不利影响。因此推测RGDV侵染可以调控昆虫种群的动态变化，进而影响病害的发生与流行。本项目拟利用介体细胞培养、免疫荧光标记、细胞自噬诱导剂和抑制剂处理、RNAi等技术体系，在细胞水平、虫体水平及田间层面，研究RGDV侵染对介体昆虫细胞自噬的影响，解析RGDV侵染调控的细胞自噬对电光叶蝉生长发育的影响，分析越冬期田间电光叶蝉细胞自噬水平与电光叶蝉带毒率及种群动态变化的关系。研究结果将解析细胞自噬调控介体电光叶蝉传播RGDV的机理，为探索病害的流行规律和制定有效的防控策略提供理论支撑。

由水稻瘤矮病毒（Rice gall dwarf virus, RGDV）引起的水稻瘤矮病主要由电光叶蝉（Recilia dorsalis）以持久增殖型方式并经卵传播。该病害是我国南方稻区重要的虫传病毒病害，并有蔓延暴发的趋势。本项目首先阐明了RGDV侵染电光叶蝉培养细胞和虫体均可激活细胞自噬“flux”，促进细胞自噬有利于病毒的积累和释放，而抑制细胞自噬则阻碍病毒的积累和释放；进一步研究发现，抑制细胞自噬不利于昆虫传毒，诱导细胞自噬有利于昆虫传毒，这表明RGDV侵染诱导的细胞自噬有利于病毒的释放和传播。此外，本项目还发现RGDV侵染显著降低介体电光叶蝉种群适合度。田间电光叶蝉种群带毒率监测进一步阐明病毒侵染不利于电光叶蝉越冬种群的繁衍，进而影响田间病害的发生与流行。研究结果阐明了RGDV间歇性暴发流行的生物学机制。因此，本项目解析了RGDV侵染诱导的细胞自噬促进病毒的高效传播；病毒侵染对介体电光叶蝉生长发育的的不利影响决定了病害间歇性暴发与流行。研究结果为探索病害的流行规律和制定有效的防控策略提供理论支撑。