最近的研究发现部分植物miRNA可以通过摄食进入昆虫体内进而调控昆虫的生长发育。但是，这类调控方式的作用机制以及所介导的植物-昆虫互作的分子机制均未见报道。本项目以水稻中的跨界miRNA osa-miR-162a为例，阐述水稻跨界miRNA进入褐飞虱的生理途径、作用机理以及对褐飞虱繁殖力的调控机制，其次深入解析褐飞虱利用内、外源miRNA分配和平衡自身代谢进而调控繁殖力的分子机制，最后阐明跨界miRNA所介导的水稻抗虫性在水稻-褐飞虱互作中的分子机制。本项目的创新之处在于率先对跨界miRNA调控植物-昆虫互作的分子机制进行系统的分析，不仅可在理论上丰富跨界miRNA及其调控机理，而且可为植物害虫互作提供新的研究思路。

In recent years, it has been found that some plant microRNAs can enter and stably exist in insect tissues through feeding, and maintain their biological activity, regulating the growth and development of insects. However, the mechanism of this kind of regulation and the molecular mechanism of plant-insect interaction have not been reported.Taking osa-microRNAs-162a in rice as an example, this project elaborated the physiological pathway and mechanism of transboundary microRNAs entering brown planthopper, as well as the regulation mechanism of reproductive capacity of brown planthopper. Secondly, it deeply analyzed the molecular mechanism of brown planthopper regulating reproductive capacity by distributing and balancing endogenous and exogenous microRNAs. Finally, it clarified the molecular mechanism of transboundary microRNAs mediating insect resistance in rice-brown planthoppe between interactions. The innovation of this project is to take the lead in systematically analyzing the molecular mechanism of cross-border microRNAs regulating plant-insect interaction, which not only enriches the theory of cross-border microRNAs and their regulation mechanism, but also provides new research ideas for pest control.