RNA interference of NADPH-Cytochrome P450 reductase increases susceptibilities to multiple acaricides in Tetranychus urticae

Abstract The two-spotted spider mite, Tetranychus urticae , is a polyphagous pest feeding on over 1,100 plant species, including numerous highly valued economic crops. The control of T. urticae largely depends on the use of acaricides, which leads to pervasive development of acaricide resistance. Cytochrome P450-mediated metabolic detoxification is one of the major mechanisms of acaricide resistance in T. urticae . NADPH-cytochrome P450 reductase (CPR) plays as a crucial co-factor protein that donates electron(s) to microsomal cytochrome P450s to complete their catalytic cycle. This study seeks to understand the involvement of CPR in acaricide resistance in urticae . The full-length cDNA sequence of T. urticae ’s CPR ( TuCPR ) was cloned and characterized. TuCPR was ubiquitously transcribed in different life stages of T. urticae and the highest transcription was observed in the nymph and adult stages. TuCPR was constitutively over-expressed in six acaricide resistant populations compared to a susceptible one. TuCPR transcriptional expression was also induced by multiple acaricides in a time-dependent manner. Down-regulation of TuCPR via RNA interference (RNAi) in T. urticae led to reduced enzymatic activities of TuCPR and cytochrome P450s, as well as a significant reduction of resistance to multiple acaricides, abamectin, bifenthrin, and fenpyroximate. The outcome of this study highlights CPR as a potential novel target for eco-friendly control of T. urticae and other related plant-feeding pests. Highlights Pipernoyl butoxide significantly reduced abamectin, bifenthrin, and fenpyroximate resistance in T. urticae populations T. urticae ’s cytochrome P450 reductase ( TuCPR ) was cloned, sequenced and phylogenetically analyzed Abamectin, bifenthrin and fenpyroximate treatment induced TuCPR gene expression Silencing of TuCPR in T. urticae caused a reduction in acaricide resistance