Metabolic functional redundancy of the CYP9A subfamily members leads to P450‐mediated lambda‐cyhalothrin resistance in Cydia pomonella

Abstract

BACKGROUND The evolution of insect resistance to pesticides poses a continuing threat to sustainable pest management. While much is known about the molecular mechanisms that confer resistance in model insects and few agricultural pests, far less is known about fruit pests. Field‐evolved resistance to synthetic insecticides such as lambda‐cyhalothrin has been widely documented in Cydia pomonella, a major invasive pest of pome fruit worldwide, and the increased production of cytochrome P450 monooxygenases (P450s) has been linked to resistance in field‐evolved resistant populations. However, the underlying molecular mechanisms of P450‐mediated insecticide resistance remain largely unknown. RESULTS Here we found that functional redundancy and preference of metabolism by P450s genes in the CYP9A subfamily confer resistance to lambda‐cyhalothrin in Cydia pomonella. A total of four CYP9A genes, including CYP9A61, CYP9A120, CYP9A121, and CYP9A122, were identified from Cydia pomonella. Among these, CYP9A120, CYP9A121, and CYP9A122 were predominantly expressed in the midgut of larvae. The expression levels of these P450 genes were significantly induced by a lethal dose that would kill 10% (LD10) of lambda‐cyhalothrin and were overexpressed in a field‐evolved lambda‐cyhalothrin resistant population. Knockdown of CYP9A120 and CYP9A121 by RNA‐mediated interference (RNAi) increased the susceptibility of larvae to lambda‐cyhalothrin. In vitro assays demonstrated that recombinant P450s expressed in Sf9 cells can metabolize lambda‐cyhalothrin, but with functional redundancy and divergence through regioselectivity of metabolism. CYP9A121 preferred to convert lambda‐cyhalothrin to 2′‐hydroxy‐lambda‐cyhalothrin, whereas CYP9A122 only generated 4′‐hydroxy metabolite of lambda‐cyhalothrin. Although possesses a relatively low metabolic capability, CYP9A120 balanced catalytic competence to generate both 2′‐ and 4′‐metabolites. CONCLUSION Collectively, these results reveal that metabolic functional redundancy of three members of the CYP9A subfamily leads to P450‐mediated lambda‐cyhalothrin resistance in Cydia pomonella, thus representing a potential adaptive evolutionary strategy during its worldwide expansion. © 2022 Society of Chemical Industry.

Functional Characterization of CYP6QE1 and CYP6FV21 in Resistance to λ-Cyhalothrin and Imidacloprid in Bradysia odoriphaga

“…45,46 Similar results have been described from studies on CYP6AE genes in Spodoptera litura and CYP9A genes in C. pomonella. 22,47 Furthermore, CYP6QE1 and CYP6FV21 were found to be most highly expressed in the midgut and Malpighian tubules, which are reported to be important tissues involved in the detoxification metabolism of xenobiotics. 14,48,49 Therefore, these results implied that the CYP6QE1 and CYP6FV21 genes may participate in the detoxification of xenobiotics.…”

“…20 The overexpression of multiple P450 genes was responsible for the high levels of permethrin resistance in a mosquito population of Culex quinquefasciatus and λcyhalothrin resistance in Cydia pomonella. 21,22 Resistance of Rhopalosiphum padi to λ-cyhalothrin is conferred by the overexpression of CYP6DC1 and CYP380C47. 23 CYP6G4, a cytochrome P450 gene overexpressed in many insecticideresistant populations of Musca domestica, has also been confirmed that it can metabolize propoxur and contributes to propoxur resistance.…”

Identification of G Protein-Coupled Receptors (GPCRs) Associated with Lambda-Cyhalothrin Detoxification in Cydia pomonella

“…A field population (ZW_R) of C. pomonella was collected from Zhangwu County, Liaoning, China, and its resistant regression strain (ZW_S) with the half-lethal dose (LD 50 ) values of 2301.58 (resistant ratio = 16.97) and 207.48 ng/μL (resistant ratio = 1.53), respectively, to lambda -cyhalothrin, were used in this study . The larvae of C. pomonella were reared using an artificial diet, and the adults were fed with 10% honey diluted with pure water. The laboratory conditions were maintained at a stable condition temperature of 26 ± 1 °C, a relative humidity of 60 ± 5%, and a photoperiod of 16:8 h (L:D).…”

“…However, the issue of resistance resulting from excessive insecticide use can no longer be disregarded. In our previous studies, we indicated that the resistance of C. pomonella to lambda -cyhalothrin is determined by multiple resistance genes such as P450 ( CpCYP9A120, CpCYP9A121 , and CpCYP9A122 ) and GST ( CpGSTd1, CpGSTd3, CpGSTe1 , and CpGSTs2 ). − These genes served as candidate genes in this study on the metabolism of insecticides. However, the transcriptional regulation of these detoxification genes has not been explored in C. pomonella .…”

Insights into the Effects of Insecticides on Aphids (Hemiptera: Aphididae): Resistance Mechanisms and Molecular Basis

“…They facilitate the coupling of electrophilic xenobiotics with reduced glutathione (GSH), which increases their water solubility and facilitates excretion [ 134 , 135 , 136 , 137 ]. Insect GSTs are the primary detoxifying enzyme and are of special importance due to their function in pesticide resistance [ 138 , 139 ]. GST enzymes are present in many insects and, being soluble and stable, their expression is stimulated by xenobiotic exposure [ 131 ], demonstrating that analogous gene regulatory mechanisms induced and overexpressed GSTs and P450s [ 51 ].…”