摘要： 毒素Ⅱ是从嗜线虫致病杆菌HB310菌株分离得到的一种具有胃毒杀虫活性的复合蛋白毒素。本研究以该毒素口服饲喂棉铃虫4龄幼虫，检测了毒素Ⅱ对棉铃虫生长发育的影响，并通过生化分析研究其对棉铃虫幼虫体内几种酶活力的影响。结果表明：饲喂拌有毒素Ⅱ人工饲料的棉铃虫4龄幼虫-化蛹历期为6.65 d，比对照明显推迟2d，毒素Ⅱ对棉铃虫幼虫化蛹有明显的影响，毒素Ⅱ饲喂的幼虫化蛹率为62%，取食对照幼虫的化蛹率为98%，并且处理组蛹的平均体重也受到明显的抑制，比对照蛹的平均体重降低106.47 mg，两者差异显著；在饲毒12 h后棉铃虫幼虫中肠弱碱性类胰蛋白酶、强碱性类胰蛋白酶、类胰凝乳蛋白酶和总蛋白酶活性分别受到抑制，到36 h饲毒幼虫与对照几种蛋白酶活性差异达到最大，分别为对照幼虫酶活性的0.3708，0.1903，0.3282和0.2141倍；饲毒12 h后毒素Ⅱ开始诱导棉铃虫幼虫体内羧酸酯酶、酯酶活性和乙酰胆碱酯酶的活性，3种酶的活性均在36 h达到最高，分别为对照的15.66，9.49，6.38倍。

关键词: 嗜线虫致病杆菌, 棉铃虫, 蛋白酶, 解毒酶, 乙酰胆碱酯酶

Abstract: ToxinⅡ, isolated from the cell of X. nematophila HB310, was an oral insecticidal protein complexes. The effects of the toxinⅡon the growth disrupting and several enzymatic activities of the Helicoverpa armigera larvae were investigated. The results indicated that the larvae period from 4th instar to pupae was 6.65 d, it remitted 2 d as compared with that of control. And the pupation rate was inhibited by toxinⅡ, the pupation rate of the treated reached 62%. The average weight of pupae was 106.47 mg, it was significantly less than that of control. The activities of weak alkaline trypsin-like enzyme, active alkaline trypsin-like enzyme, chymotrypsin-like enzyme and total protease in the toxin-treated midgut were inhibited significantly at 36 h, which were 0.3708, 0.1903, 0.3282 and 0.2141 times of those of the control respectively. On the other hand, the activities of carboxylesterase, esterase and acetylcholinesterase in the toxintreated midgut were peaks at 36 h, which were 15.66, 9.49 and 6.38 times than those of the control respectively.

Key words: Xenorhabdus nematophila, Helicoverpa armigera, Protease, Detoxicating enzyme, Acetylcholinesterase

中图分类号: 

• S482