昆虫中肠蛋白酶是蛋白质类食物消化与利用的重要酶系，同时对蛋白质类毒物具有解毒作用。稻纵卷叶螟是水稻上重要的两迁害虫之一，Bt蛋白对其有较好的杀虫活性，是常用的生物杀虫剂。深入研究该虫中肠蛋白酶分子特性对于明确稻纵卷叶螟的消化生理具有重要作用，有助于揭示其对Bt蛋白的降解功能，延缓抗性的产生。本项目在前期对稻纵卷叶螟中肠蛋白酶液生化特性研究的基础上，通过稻纵卷叶螟中肠转录组测序的方法全面挖掘其中肠蛋白酶基因，克隆中肠蛋白酶基因全长、分析蛋白酶基因结构及其相对表达谱，利用RNAi技术研究分析中肠蛋白酶对Bt蛋白的降解功能。研究结果将有利于基于中肠蛋白酶的新型防控技术的开发与利用，有利于害虫对Bt蛋白抗性治理策略的制定，提高稻纵卷叶螟的综合治理效果。

Midgut proteinases are crucial enzymes in insect to digest and utilize the protein foods. They are also important to detoxify the protein toxins. Cnaphalocrocis medinalis is one of main migratory insect pests in paddy fields. Bt protein as widely-used bio-insecticide harbored high insecticidal activity against C. medinalis. Further studies on the molecular characters of midgut proteinases play a significant role on understanding of the digestive physiology and their function on degradation of Bt protein and delaying the resistance. Based on previous studies on biochemical properties of the midgut proteinase in C. medinalis, in this project we will dig the midgut proteinase genes through midgut transcriptome sequencing, validate full-length of proteinase genes, analyze the genes’ structures and their expression profiles, and valuate the degradation function of proteinase against Bt protein by RNAi. The results of this project will promote the development and utilization of new control technology based the midgut proteinase, and facilitate the workout of resistant management tactic of C. medinalis against Bt protein, and enhance the efficacy of the integrated management of C. medinalis in paddy field.