Panonychus citri is a globally distributed pest that is currently controlled using insecticides. However, alternative strategies are needed to minimize the use of chemicals. Given that the enormous potential of RNA interference pesticides in pest control development, lipases also have key roles in underpinning insect reproduction, development, defence from pathogens and oxidative stress, and pheromone signalling.Therefore, studying the function of Gastric lipase as a control measure for P. citri may be a promising approach. In this study, we cloned PcGTGL from the genome and studied its transcriptional response to spirobudiclofen, as well as its response after PcGTGL was knocked down. The results showed that the expression level of PcGTGL was higher during the larval、deutonymph and adult stage compared to the stage of egg. Additionally, under the stress of spirobudiclofen, the expression level decreased with the concentration of insecticides increased. We silenced PcGTGL through RNAi, and the results indicated an increase in mortality rate of P. citri, as well as a lethal phenotype characterized by body folding and darkening. Additionally, we found that treatment with spirobudiclofen on PcGTGL-silenced P. citri not only increased mortality rates and the mRNA expression of hormone-sensitivelipase(HSL), but also led to lower expression levels of PcGTGL、PcVg 、PcVgR and accumulation of TAG. These results indicate that the silencing of PcGTGL effectively inhibits the population growth of P. citri. Following the inhibition of PcGTGL, P. citri helps them obtain the energy needed to resist insecticide stress by triggering HSL action. The results provide a new RNAi-based target for control of P. citri.
Read full abstract