四种P450基因调控小菜蛾对氯虫苯甲酰胺的抗性

为研究CYP6家族P450基因在小菜蛾Plutella xylostella代谢氯虫苯甲酰胺中的作用，利用浸叶法测定不同小菜蛾种群3龄幼虫对氯虫苯甲酰的抗性水平，采用实时荧光定量PCR(quantitative realtime PCR,q RT-PCR)方法分析CYP1v3、CYP1v4、CYP6B6和CYP6f这4种P450基因在小菜蛾不同抗性种群体内的表达差异及杀虫剂的短期诱导效应，并通过RNA干扰技术沉默4种P450基因后分析小菜蛾对氯虫苯甲酰胺的敏感性。结果显示，4种P450基因在中等抗性水平小菜蛾种群体内高表达；氯虫苯甲酰胺处理可诱导4种基因显著上调表达。分别沉默4种P450基因后，处理组小菜蛾的P450酶活力显著下降37.60%～54.82%，且处理组小菜蛾的死亡率显著高于对照组；同时沉默4种基因处理组的小菜蛾P450酶活力显著低于其他各处理组。表明4种P450基因可能同时参于小菜蛾对氯虫苯甲酰胺的代谢。

Regulation of the resistance of diamondback moth Plutella xylostella to chlorantraniliprole by four cytochrome P450 genes

To clarify the function of four CYP6 family P450 genes in the metabolism of chlorantraniliprole in diamondback moth Plutella xylostella, the resistance levels of the 3rd-instar larvae of different P. xylostella populations to chlorantraniliprole were determined with leaf dip method. The expression differences of four P450 genes (CYP1v3, CYP1v4, CYP6B6 and CYP6f) in different resistant populations of P. xylostella and the short-term induction effects of insecticides were analyzed by quantitative realtime PCR (qRT-PCR). After silencing the four P450 genes by RNA inference (RNAi), the sensitivity of P. xylostella to chlorantraniliprole was analyzed. The results showed that four P450 genes were highly expressed in moderately resistant population of P. xylostella. The expression of the four genes was significantly up-regulated by chlorantraniliprole. After silencing the four P450 genes by RNAi, the activity of P450 was significantly decreased by 37.60%-54.82%. The mortality of P. xylostella in the treatment group was significantly higher than that in the control. The activity of P450 after simultaneously silencing the four genes was lower than that in other treatments. The results indicated that the four P450 genes might be involved in the metabolism of chlorantraniliprole in P. xylostella.