抗双酰胺类杀虫剂小菜蛾的cDNA代表性差异分析

cDNA Representational Difference Analysis in Plutella xylostella Resistant to Diamide Insecticides

小菜蛾(Plutella xylostella L.)为世界性十字花科蔬菜的重要害虫之一,由于其繁殖力较强,世代重叠严重,加上一些地区生产上用药频繁,导致小菜蛾对多种杀虫剂产生了抗性。随着氯虫苯甲酰胺和氟苯虫酰胺等双酰胺类杀虫剂的大量应用,小菜蛾对该药剂的抗性问题也日益受到关注。为了研究小菜蛾对双酰胺类杀虫剂的抗性机制,本试验利用敏感品系cDNA作为"驱动子"(Drivers),小菜蛾抗氯虫苯甲酰胺品系、抗氟苯虫酰胺品系cDNA作为"检测子"(Testers),通过改进的cDNA代表性差异分析法(cDNA rrepresentational difference analysis,cDNA RDA),在小菜蛾抗氯虫苯甲酰胺品系、抗氟苯虫酰胺品系中获得2个与28S rRNA基因有较高同源性的序列,其中一个序列(DP3-1)与棉铃虫细胞色素P450类TBP蛋白同源性为97%,另外一个序列(DP3-2)与赤拟谷盗的TcasGA2_TC010626蛋白基因同源性为93%;此外,两个抗性品系中各获得一个未知序列。本研究为进一步探讨小菜蛾对双酰胺类杀虫剂的抗性机制提供了新线索。

Diamondback moth, Plutella xylostella （Lepidoptera： Plutellidae）, is a worldwide pest of cruciferous vegetables. This is probably due to its high fecundity, serious overlapping generation and frequent over - use of insecticides, which led to the resistance of diamondback moth to muhiple insecticides. The extensive use of diamide insecticides such as chlorantraniliprole and flubendiamide has caused more and more concerns of researchers on the resistance of P. xylostella to them. In order to study the resistance mechanism of P. xylostella to diamide insecticides, the cDNA of susceptible strain （S） was used as the ＂Drivers＂ and the cDNA of the chlorantraniliprole resistant strain （ Rf ） and flubendiamide resistant strain （ Rh ） were used as ＂Testers＂; the approved cDNA representational difference analysis （cDNA RDA） was used to screen the difference gene sequences. Two fragments were obtained with high homology with 28S rRNA gene from the Rf and Rh strains. One of the two sequences （ DP3 - 1 ） was 97% homologous to the cytochrome P450 TBP pro- tein of Helicoverpa armigera, and the other sequence （DP3 -2） was identical to the TcasCA2_TC010626 pro- tein gene of Tribolium castaueum with the homology of 93 %. In addition, one unknown sequence was also ob-tained from each of the two resistant strains. This study provided new clues for further research on the resist- ance mechanism of P. xylostella to the two amide insecticides.