豌豆蚜组织蛋白酶cathB-3098响应球孢白僵菌侵染的分子机制

蚜虫是全世界广泛分布危害的刺吸式害虫，球孢白僵菌Beauveria bassiana是重要的生防真菌，然而蚜虫的免疫系统限制了球孢白僵菌的防控效力。真核生物cathepsin B可通过响应病原物侵染以诱导细胞凋亡，继而激活吞噬作用进行免疫。本项目前期分析表明，豌豆蚜组织蛋白酶基因cathB-3098响应球孢白僵菌的侵染，但是响应机制尚不明确。围绕此科学问题，本项目进行以下研究工作：（1）采用生物信息学和时空表达分析cathB-3098基因的基本特征；（2）利用表达动力学、亚细胞定位、RNAi和抑制剂试验解析cathB-3098响应球孢白僵菌的功能；（3）通过异源表达、RNAi和抑制剂试验明确cathB-3098介导的细胞凋亡与吞噬作用之间的关系。本项目研究结果将不仅揭示豌豆蚜cathB-3098介导的免疫机制，还将为蚜虫的微生物防控提供新思路。

Aphids, a sap-sucking agricultural pest, are distributed worldwide. The Beauveria bassiana is an important green entomopathogenic fungus for pest control. However, the control effect of B. bassiana against aphids was limited by the immune system of aphid. Eukaryotic cathepsin B provides immunity by inducing apoptosis in response to pathogen infection and subsequently activating phagocytosis. In this project, the previous analysis showed that the cathB-3098, a cathepsin gene from pea aphid, responded to B. bassiana infection, but the mechanism remains unclear. Based on this scientific problem, the following research work will perform in this project: (1) The primary characteristics of cathB-3098 gene were analyzed by bioinformatics and spatio-temporal expression profile. (2) The role of cathB-3098 in response to B. bassiana was analyzed by expression kinetics, subcellular localization, RNAi and inhibitor assay. (3) The relationship between cathB-3098-mediated apoptosis and phagocytosis was determined by the heterologous expression, RNAi and inhibitor assay. Our results will not only reveal the immune mechanism mediated by cathB-3098 of pea aphid, but also provide new ideas for aphid control by microbial agents.