Abstract: 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.

Key words: Plutella xylostella, IGluR, abamectin, RNA interference, action target