嗜线虫致病杆菌杀虫毒素对棉铃虫的中肠组织病理学研究  

Histopathological Effects of the Protein Toxin from Xenorhabdus nematophila on the Midgut of Helicoverpa armigera

作　　者：南宫自艳[1] 王勤英[1] 宋萍[1] 杨君[1] 毛文杰[1] 

机构地区：[1]河北农业大学植物保护学院河北省农业病虫害生物防治工程技术研究中心,保定071001

出　　处：《中国农业科学》2005年第11期2240-2245,共6页Scientia Agricultura Sinica

基　　金：国家自然科学基金项目(30400296)资助

摘　　要：嗜线虫致病杆菌HB310菌株与小卷蛾斯氏线虫HB310共生,对多种昆虫均具有较高生物活性。本实验通过盐析和非变性凝胶电泳等方法从嗜线虫致病杆菌HB310菌株的细胞内分离纯化出具胃毒活性的蛋白毒素Ⅱ。经毒素Ⅱ处理的棉铃虫幼虫,中肠组织的病理学变化类似于发光杆菌Tca毒素和Btδ-内毒素。棉铃虫4龄幼虫口服毒素Ⅱ6h后中肠组织开始发生变化:首先围食膜前端破碎,中肠柱状细胞伸长;随着时间推移,12h后整个围食膜被破坏消失,中肠组织病变加重,肠壁细胞排列疏松混乱;随着毒素作用的逐渐减弱,处理72h后棉铃虫中肠围食膜又重新出现。毒素Ⅱ离体处理棉铃虫围食膜,同样可以导致围食膜破碎。Xenorhabdus nematophila HB310 is highly virulent to many insects, and it is symbiotic with Steinernema carpocapsae HB310. Toxin Ⅱ was obtained by salting out and native-PAGE from the cells of X. nematophila HB310. The histopathology of toxin Ⅱ to Helicoverpa armigera larvae was studied by dissecting and olefin slice of the midgut. The symptoms showed that the histopathology of the H. armigera midgut was similar to that of other novel midgut-active toxins such as the δ-endotoxins from Bacillus thuringiensis, as well as Tca from Photorhabdus luminescens W14. The midgut tissues of H. armigera fouth-instar larvae began to change after taken the toxin II orally in 6 hours. The foreport of peritrophic membrane began fracture and the cells extended. The epithelium was decomposed gradually and the midgut tissues were loose or disordered at last. The peritrophic membrane disappeared after 12 hours but appeared again after 72 hours following transient or sublethal exposure to the toxin. The toxin Ⅱ also directly destroyed the excised peritrophic membrane of H. armigera.

关 键 词：嗜线虫致病杆菌 毒素 棉铃虫 中肠 组织病理学 

分 类 号：S476.11[农业科学—农业昆虫与害虫防治]