The Roles of Four Novel P450 Genes in Pesticides Resistance in Apis cerana cerana Fabricius: Expression Levels and Detoxification Efficiency

Abstract

Cytochrome P450 monooxygenases (P450s) are widely distributed multifunctional enzymes that play crucial roles in insecticide detoxification or activation. In this study, to ascertain the molecular mechanisms of P450s in the detoxification of Chinese honeybees, <i>Apis cerana cerana</i> Fabricius (<i>A. c. cerana</i>), we isolated and characterized four new P450 genes (<i>Acc301A1</i>, <i>Acc303A1</i>, <i>Acc306A1,</i> and <i>Acc315A1</i>). The open reading frames of the four genes are 1263 to 1608 bp in length and encode four predicted polypeptides of 499 to 517 amino acids in length. Real-time quantitative PCR (RT-qPCR) results showed that expression of all four genes was observed in all developmental stages. In addition, Western blot assays further indicated the RT-qPCR results that showed that the four genes were induced by pesticide (thiamethoxam, deltamethrin, dichlorovos, and paraquat) treatments. Furthermore, we also used double-stranded RNA-mediated RNA interference to investigate the functions of <i>Acc301A1</i>, <i>Acc303A1</i>,and <i>Acc306A1</i> in the antioxidant defense of honeybees. RNA interference targeting <i>Acc301A1</i>, <i>Acc303A1</i>, and <i>Acc306A1</i> significantly increased the mortality rate of <i>A. c. cerana</i> upon pesticide treatment. These results provide important evidence about the role of the four P450 genes involved in detoxification.