小菜蛾抑制性谷氨酸受体的RNA干扰

RNA interference of the inhibitory glutamate receptor in Plutella xylostella (Lepidoptera: Plutellidae)

谷氨酸门控的氯离子通道(glutamate-gated chloride channels,GluCls)或抑制性谷氨酸受体(inhibitory glutamate receptor,IGluR)是阿维菌素类药剂(avermectins)主要的作用靶标,目前人们对于昆虫的IGluR知之甚少。本实验采用RNA干扰(RNAi)技术对小菜蛾Plutella xylostella IGluR的功能进行了初步研究。结果表明:小菜蛾2龄和3龄幼虫中双链RNA(dsRNA)的最佳注射量分别为50.6nL和71.3nL。实时荧光定量(quantitative real-time PCR,qRT-PCR)检测结果表明,2龄和3龄幼虫在注射dsRNA 36h和24h后IGluR基因的转录后水平分别下降了32.67%和49.30%。幼虫发生RNA干扰后对阿维菌素的敏感性结果显示,注射了IGluR dsRNA的幼虫死亡率显著低于对照。结果说明,小菜蛾IGluR是阿维菌素的潜在靶标之一,为进一步阐明小菜蛾对阿维菌素靶标抗性机理奠定了基础。

Glutamate-gated chloride channels （GluCls） or inhibitory glutamate receptor （IGluR） is the major action targets of avermectins. However, people have little knowledge of IGluR in insects currently. In this preliminary experiment, RNA interference （RNAi） technology was used to study the function of the IGluR in Plutella xylostella. The results showed that the most suitable injection volumes of double strand RNA （dsRNA） for the 2nd and 3rd instar larvae were 50.6 nL and 71.3 nL, respectively. The results of quantitative real-time PCR （qRT-PCR） showed that the post transcriptional level of IGluR in the 2nd instar larvae decreased by 32.67% at 36 h after RNAi and that in the 3rd instar larvae decreased by 49.30% at 24 h after RNAi. The susceptibility of larvae after RNAi to abamectin revealed that the mortality of the larvae injected with the dsRNA of IGluR was significantly lower than that of the control. The results suggest that the IGluR in P. xylostella is a potential target site for abamectin, and these results would lay the foundation for further elucidation of the target resistance mechanism of P. xylostella to abamectin.