褐飞虱谷胱苷肽转移酶基因cDNA片段的克隆、测序及表达分析

谷胱苷肽转移酶是昆虫体内重要的解毒酶系之一，研究水稻害虫褐飞虱的谷胱苷肽转移酶基因在褐飞虱与水稻互作中的表达变化，可为有效防治褐飞虱提供新的理论依据。利用反转录多聚酶链式反应（RTPCR）技术克隆了褐飞虱谷胱苷肽转移酶基因编码区的eDNA片段，并使用Northern杂交技术检测了该基因对两种不同抗性水稻的分子反应。结果表明，所克隆到的eDNA片段长度为201bp，该片段所编码的氨基酸序列与来自大劣按蚊、细小按蚊、冈比亚按蚊、果蝇和木瓜果实蝇的谷胱苷肽转移酶的片段存在高度同源性。Northern杂交显示，在褐飞虱取食抗性水稻后，谷胱苷肽转移酶基因表达水平明显升高，但褐飞虱取食感虫水稻TN1后，该基因的表达水平没有明显变化。

Cloning and expression of glutathione S-transferase gene from brown planthopper Nilaparvata lugens

Glutathione S-transferase is one of the most important detoxification enzymes in insects. Cloning and expression analysis of this gene in brown planthopper Nilaparvata lugens will help in the design of effective programs for controlling the rice pest. A RT PCR strategy was used to clone a cDNA fragment of glutathione S-transferase gene from brown planthopper. The expression alteration of this gene in response to two different rice varieties was examined by Northern blot hybridization. The results show that the length of the cDNA fragment is 201 bp in size, and the amino acid sequence deduced from the cDNA fragment has a high homology with parts of glutathione S-transferases from Anopheles dirus, opheles cracens, opheles gambiae, osophila erecta and actrocera papayae. Northern hybridization analysis shows that the expression of this gene rapidly increases after brown planthopper is fed with resistant rice BS, but it remains at a constant expression level in brown planthopper exposed to susceptible rice TN1.