喂食Cry1Ac毒素对棉铃虫中肠类胰蛋白酶的影响  

Influence of the Ingestion of Cry1Ac Toxin on Trypsin-Like Protease in Helicoverpa Armigera Midgut

作　　者：袁灿[1] 夏立秋[1] 丁学知[1] 田野[1] 尹佳[1] 

机构地区：[1]湖南师范大学生命科学学院、微生物分子生物学湖南省重点实验室,中国长沙410081

出　　处：《湖南师范大学自然科学学报》2009年第2期93-97,共5页Journal of Natural Science of Hunan Normal University

基　　金：国家863计划资助项目(2006AA10A212,200602Z187);国家自然科学基金资助项目(30670052,30870064);教育部博士点基金资助项目(20060542006);湖南省自然科学基金优秀面上资助项目(06JJ2009)

摘　　要：苏云金芽胞杆菌(Bacillus thuringiensis,Bt)在芽胞形成过程中产生的原毒素被敏感昆虫吞食进入消化道后,在中肠蛋白酶的作用下经历一系列酶的剪切活化过程,形成具有杀虫活性的毒性肽.类胰蛋白酶因其在昆虫中肠内蛋白质水解和Bt毒素活化中起着重要作用而受到广泛研究.本研究提取了棉铃虫4龄幼虫的中肠BBMV蛋白,利用SDS-PAGE分析鉴定到喂食Cry1Ac毒素24h后,棉铃虫幼虫中肠类胰蛋白酶的表达量呈明显下降趋势.该下降趋势很有可能是作为一种昆虫对Bt毒素作用的早期反应,通过影响Bt毒素在中肠中的酶解活化过程,从而为昆虫提供即时保护.The protoxin produced by Bacillus （Bt） during the sporulation phase is cleaved by midgut proteases to a stable toxin core. Trypsin-like protease is widely studied because of its important role in the activation process. In this study, BBMV proteins from the fourth instar larvae of Helicoverpa armigera before and 24 h after ingestion of Bt CrylAc toxin are prepared. SDS-PAGE separation of the BBMV proteins shows a dramatic decrease in the level of trypsin-like protease 24 h protease in the larval midgut is important during after ingestion of Bt Cryl Ac toxin. The decrease of trypsin-like early responses and adaptation of the insect to Bt, and this decrease can provide immediate protection to the larva by reducing the activation of Bt toxin.

关 键 词：苏云金芽胞杆菌 棉铃虫 CRY1AC 类胰蛋白酶 

分 类 号：Q936[生物学—微生物学]