羧肽酶在Bt抗性棉铃虫中肠的表达分析  

Analysis of midgut carboxypeptidase expression in Bt-resistant Helicoverpa armigera

作　　者：张永栋[1,2] 刘晨曦[2] 何林[1] 张锋[2,3] 吴孔明[2] 

机构地区：[1]西南大学植物保护学院,重庆市昆虫学及害虫控制工程重点实验室,重庆400716 [2]中国农业科学院植物保护研究所,植物病虫害生物学国家重点实验室,北京100193 [3]陕西省动物研究所,西安710032

出　　处：《环境昆虫学报》2011年第2期159-165,共7页Journal of Environmental Entomology

基　　金：国家重点基础研究发展计划(2007CB109204)

摘　　要：本研究利用实时定量PCR技术检测了对Bt(Bacillus thuringiensis)Cry1Ac敏感和抗性品系棉铃虫Helicov-erpa armigera中肠羧肽酶(carboxypeptidase)的mRNA表达,发现在抗性品系中羧肽酶表达量明显下降(约2.6倍);中肠汁液中羧肽酶酶活测定结果表明,抗性品系羧肽酶酶活性同样显著下降约2.2倍。羧肽酶作为重要的消化性外切酶(exopeptidase),能够消化摄取食物中的大量可吸收的蛋白质,抗性品系羧肽酶表达量显著下降表明该种群消化食物的能力降低,这可能会导致与抗性适合度相关的多种生理指标的下降。另外,体外成功表达棉铃虫羧肽酶,为从蛋白和抗体水品进一步研究羧肽酶在棉铃虫抗性适合度中的作用奠定基础。Carboxypeptidase mRNA expression level was detected in the midgut of Cry1Ac susceptible and resistant Helicoverpa armigera larvae by using real-time quantitative PCR.The carboxypeptidase levels were much reduced in the larvae of Cry1Ac-resistant strain of H.armigera compared to susceptible ones（2.6 fold）.The result of carboxypeptidase activity in midgut juice showed consistant reduction in resistant strain with about 2.2 fold.As a key digestive exopeptidase,carboxypeptidase can digest a mass of absorbent proteins from food.Because of significant reduction of carboxypeptidase activity,decrease of food digestive capability might lead to fitness cost in resistant strain.Besides,the recombinant H.armigera carboxypeptidase was heterogenous expressed in E.coli.This will facilitate the further study on the funtion of carboxypeptidase related to fitness cost at protein and immune level.

关 键 词：羧肽酶 适合度代价 实时定量PCR 酶活 原核表达 

分 类 号：Q965[生物学—昆虫学]