靶标害虫Bt作用机理的研究将为Bt抗性的监测与治理提供重要的理论指导。ABCC2是鳞翅目昆虫重要的Bt毒素受体，最新的研究发现其他三种ABC转运体，ABCA2，ABCC3和ABCG1分别在棉铃虫、斜纹夜蛾和小菜蛾里参与介导Bt毒素的杀虫功能。本项目拟以重要的Bt靶标害虫棉铃虫为研究对象，通过基因克隆获得ABCG1基因的全长序列，构建真核表达载体转染Hi5细胞系，用Cry1Ac和Cry2Ab处理细胞，分析ABCG1介导不同毒素的穿孔作用；进一步在棉铃虫体内利用RNAi的方法下调表达ABCG1，通过Cry1Ac和Cry2Ab两种毒素的生测实验验证目标基因参与介导不同Bt毒素杀虫的功能。本项目将综合以上两个方面的工作，深入解析ABC 转运体重要成员ABCG1识别并介导Bt毒素杀虫的机制，为Bt毒素作用机理的研究和可能的新Bt抗性机制发现做出重要贡献。

Research of Bt (Bacillus thuringiensis) functional mechanism on taget pest will supply directions on monitor and management of Bt resistance. ABCC2 (ATP-Binding Cassette Sub-Family C Member2) is key receptor of Bt toxins in Lepidoptera, and new research reported that ABCA2，ABCC3 and ABCG1 had important roles in Bt insecticidal actions in Helicoverpa armigera, Spodoptera litura and Plutella xylostella respectively. This research will clone the full length of ABCG1 in Helicoverpa armigera, and restructure eukaryotic expressional vector to transfect Hi5 cells. Then Cry1Ac and Cry2Ab will be used to treat restructured Hi5 cells to analyzed ABCG1 mediated Bt insecticidal action. We will down-regulate expression of ABCG1 with RNAi and make bioassay with Cry1Ac and Cry2Ab to prove the function of ABCG1 in mediating insecticidal action of different Bt toxin. This project will make important contributions to Bt functional research and new finding of Bt resistant mechanism.