Silencing NADPH-Cytochrome P450 reductase affects imidacloprid susceptibility, fecundity, and embryonic development in Leptinotarsa decemlineata

ABSTRACTThe Colorado potato beetle (CPB) is a prominent insect pest of potatoes, tomatoes and eggplants all over the world, however, the management of CPB remains a challenging task for more than one hundred years. We have successfully developed bacteria-expressed dsRNA-mediated feeding RNA interference (RNAi) approach in our previous study. A critical step towards field management of CPB via feeding RNAi is to identify effective and environmentally safe target genes. NADPH-Cytochrome P450 reductase (CPR) plays a central role in cytochrome P450 action. The full length Leptinotarsa decemlineata CPR (LdCPR) cDNA was isolated from an imidacloprid resistant population. The LdCPR gene was ubiquitously expressed in all stages tested but showed an increase in expression during the early stage of embryonic development. The bacteria-expressed dsRNA-mediated feeding RNAi of LdCPR in adults caused systemic knock down expression of the gene coding for LdCPR in both adults and their eggs. Suppression of LdCPR expression increased susceptibility of imidacloprid in resistant beetles, as well as a significant decrease of fecundity in female beetles (29% less eggs/day) and the hatching rate (47%) of their eggs. These data suggest that LdCPR plays important roles in insecticide detoxification and biosynthetic pathways of endogenous compounds and may serve as an essential target to control CPB.HIGHLIGHTSHigh expression of LdCPR was observed in the egg stage.Silencing of LdCPR reduced the CPR enzymatic activities.LdCPR knockdown increased imidacloprid susceptibility.LdCPR knockdown decreased the fecundity and enhanced embryonic lethality.

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

10.1101/780536 ◽

2019 ◽

Author(s):

Adekunle W. Adesanya ◽

Antonio Cardenas ◽

Mark D. Lavine ◽

Doug B. Walsh ◽

Laura C. Lavine ◽

...

Keyword(s):

Cytochrome P450 ◽

Rna Interference ◽

Tetranychus Urticae ◽

Cytochrome P450s ◽

List Type ◽

Cytochrome P450 Reductase ◽

Acaricide Resistance ◽

Nadph Cytochrome ◽

P450 Reductase ◽

Nadph Cytochrome P450 Reductase

AbstractThe 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.HighlightsPipernoyl butoxide significantly reduced abamectin, bifenthrin, and fenpyroximate resistance in T. urticae populationsT. urticae’s cytochrome P450 reductase (TuCPR) was cloned, sequenced and phylogenetically analyzedAbamectin, bifenthrin and fenpyroximate treatment induced TuCPR gene expressionSilencing of TuCPR in T. urticae caused a reduction in acaricide resistance

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