稻纵卷叶螟一个DELTA家族谷胱甘肽S-转移酶基因的克隆、序列分析与表达模式

摘要

谷胱甘肽S-转移酶（glutathione S-transferases ，GSTs）在昆虫代谢各种内源和外源性有害化合物的过程中起关键作用。重要水稻害虫稻纵卷叶螟（Cnaphalocrocis medinalis）的GST基因目前尚无研究。本实验克隆了一个稻纵卷叶螟delta家族GST基因的全长cDNA序列，命名为CmGSTd3（Genbank登录号KM433686）。CmGSTd3包含681 bp的开放阅读框，编码一个由226个氨基酸组成的蛋白。CmGSTd3蛋白是一个胞质GST ，与已知的昆虫delta家族GST 具有较高的同源性。在系统进化分析中，CmGSTd3与家蚕的delta家族GST聚在同一进化分支上。实时荧光定量PCR结果显示，CmGSTd3基因在稻纵卷叶螟幼虫阶段表达量最高，且主要表达于幼虫的中肠和脂肪体，由此推测其可能参与了体内异源毒物的代谢。本研究为探索CmGSTd3的生理功能奠定了前期基础。%In insects ,glutathione S-transferases (GSTs) play essential roles in the detoxification of a variety of harmful endobiotics and xenobiotics .However ,information about the GST genes in the rice leaf folder ,Cnaphalocrocis medinalis (Lepidoptera:Pyralidae) ,is still unavailable .In the present study ,a 681 bp cDNA (named CmGSTd3 ,Genbank No .KM433686) encoding a 226 amino acids GST was isolated from C .medinalis .CmGSTd3 protein was a cytosolic GST belonging to delta class .The protein show a high identity with delta-class GSTs identified from other moth species ,and were clustered in a branch with a delta GST of Bombyx mori in phylogenetic analysis .Real-time quantitative PCR analysis showed that CmGSTd3 mRNA was mainly expressed in the larval stage ,and highly expressed in midgut and fat body of the larvae .The present study paves the way for understanding the physiological function of the CmGSTd3 .