持久增殖型植物病毒如何与媒介昆虫的免疫系统互作，实现有限增殖而不使昆虫介体致死，是媒介生物学领域的研究热点。酚氧化物酶原激活系统（PPO）是无脊椎动物抵御细菌和真菌的重要免疫通路之一，但对病毒的免疫作用报道非常少。本项目以灰飞虱与其传播的水稻条纹病毒RSV为研究体系，基于前期实验发现RSV的CP蛋白能够结合灰飞虱PPO通路上的酚氧化酶原激活因子II，本项目拟探讨RSV如何调控媒介昆虫PPO免疫通路，实现与媒介昆虫共存的科学问题。研究内容包括灰飞虱的PPO通路基因对RSV侵染的响应、RSV对PPO酶活的影响、RSV调控PPO酶活的机制、PPO通路对RSV复制的影响等四个方面，从基因表达、蛋白互作、酶活检测、病毒复制多层面解析RSV与媒介昆虫PPO通路的关系。研究结果不仅是媒介生物学的重要突破，而且为未来通过操纵昆虫PPO通路实现从源头控制水稻条纹病毒流行暴发奠定理论基础。

How persistent-propagative plant viruses proliferate in a limited level through interaction with the immune system of insect vectors is a research hotspot of vector biology. Prophenoloxidase (PPO) activating system is one of the most important immune pathways to defend against pathogens such as bacteria and fungi in invertebrates. However, few cases have been reported for PPO functions in virus immunity. In the present project, we use the system of small brown planthopper and its transmitted Rice stripe virus (RSV) to explore how RSV erects a compatible relation with insect vectors by regulating the PPO pathway, based on our preliminary finding of the interaction between the virus capsid protein CP and insect PPAF2, an activation factor of PPO. The main aspects of this project includes the response of PPO pathway genes to RSV infection, the influence of RSV on PPO enzymatic activity, the regulation mechanisms of RSV to PPO enzymatic activity, and the effect of PPO on RSV proliferation in insect vectors. The relation between the PPO system and RSV in insect vectors will be dissected from gene expression, protein-protein interaction, enzymatic assay, and virus replication. The outcome of this project will be a breakthrough in vector biology, and provide a theory basis for manipulating insect PPO pathway to control the outbreak of rice stripe disease in future.