PuGV-Ps对甜菜夜蛾中肠液酶解δ-内毒素的影响  

Impact of Psedualetia unipuncta granulovirus on the degradation of δ-endotoxin by midgut juice from Spodoptera exigua

作　　者：徐健[1] 刘琴[2] 祝树德[1] 

机构地区：[1]扬州大学园艺与植物保护学院,江苏扬州225009 [2]江苏里下河地区农业科学研究所,江苏扬州225007

出　　处：《扬州大学学报（农业与生命科学版）》2008年第1期79-84,共6页Journal of Yangzhou University：Agricultural and Life Science Edition

基　　金：中国科学院农业病虫鼠害研究国家重点实验室开放课题(IPM0703);国家“十一五”科技支撑计划项目(2006BAD02A03);江苏省研究生培养创新工程项目(CX07B-1902);江苏省太湖治理专题项目(BS2007143)

摘　　要：粘虫颗粒体病毒（PuGV-Ps）总蛋白酶活力测定表明,PuGV-Ps在pH7.38～10.38范围内均具有蛋白酶活性,且酶活力随pH的升高而显著提高。4种蛋白酶抑制剂均能抑制PuGV-Ps的蛋白酶活力,以大豆胰蛋白酶抑制剂的抑制作用最强,表明PuGV-Ps的蛋白酶活性是以胰蛋白酶为主要活力的多种蛋白酶的活性特征。PuGV-Ps对甜菜夜蛾（Spodoptera exigua）中肠酶液离体蛋白酶活力及取食PuGV-Ps后总蛋白酶活力的影响测定表明,在中肠液酶适宜pH（9.38～10.38）范围内,PuGV-Ps在一定程度上抑制了中肠酶液的总蛋白酶活力。SDS-PAGE试验表明,PuGV-Ps影响甜菜夜蛾中肠酶液对苏云金杆菌（Bacillus thuringiensis）δ-内毒素的降解活化作用,表现在对130ku的δ-内毒素酶解活化成60～87ku的活性多肽影响不大,但对其进一步降解具有抑制作用。不同缓冲液同样影响甜菜夜蛾中肠酶液对δ-内毒素的降解,Na2CO3是影响降解程度的重要因子。Total proteolysis of PuGV-Ps was measured by using azocasein under different pH conditation from value 7.38 to 10.38, and the proteolytic effect was improved following the rising of pH value. All the four kinds of protein enzyme inhibitors inhibited the activity of PuGV-Ps proteolysis, which indicated the proteolytic activity of PuGV-Ps was due to several proteases, mainly from trypsin-like enzyme. The proteolytic activity of midgut juice from Spodotera exigua was influenced by PuGV-Ps. Under the suitable pH value of midgut juice, the total proteolysis was reduced for some degree by PuGV-Ps. SDS-PAGE analysis showed that PuGV-Ps also influenced the degradation of δ-endotoxin of Bacillus thuringiensis by midgut juice from S. exigua. The yielded of active toxin proteins from 60 to 87 ku was not influenced obviously by PuGV-Ps, but the further degradation of activated toxin was inhibited. Degradations of δ-endotoxin by midgut juice in different buffers were also different, indicated that the saline of Na2CO3 was the important factor to increase the further degradation of δ-endotoxin.

关 键 词：甜菜夜蛾 中肠酶液 粘虫颗粒体病毒 δ-内毒素 

分 类 号：S436.341.2[农业科学—农业昆虫与害虫防治]