Enantioselective metabolism of fenpropathrin enantiomers by carboxyl/choline esterase 6 in Tetranychus cinnabarinus

Abstract BACKGROUND Tetranychus cinnabarinus is a polyphagous pest mite commonly found in agriculture. As an excellent acaricide, fenpropathrin (FEN) is frequently used to control T. cinnabarinus in agriculture. However, commercial FEN is a racemate with two enantiomers, R ‐FEN and S ‐FEN. Considering that investigations on the metabolism of FEN by T. cinnabarinus are based on racemate FEN, it is important to investigate the enantioselective metabolism of FEN in T. cinnabarinus . RESULTS S ‐FEN was more toxic to T. cinnabarinus than R ‐FEN by more than 68.8‐fold. Moreover, the synergist bioassay revealed that carboxylesterase and cytochrome P450 were the primary enzymes engaged in the detoxification of FEN in T. cinnabarinus , with carboxylesterase playing a leading role. Seven genes were substantially different after the induction of S ‐FEN and R ‐FEN. TcCCE06 was screened and selected as a key gene that related to FEN metabolism in T. cinnabarinus. The metabolic results showed that the recombinant TcCCE06 effectively metabolized 32.1% of the R ‐FEN and 13.8% of the S ‐FEN within 4 h of incubation. Moreover, R ‐FEN was demonstrated to have a higher affinity for the TcCCE06 protein than S ‐FEN based on molecular docking. CONCLUSION Our results indicated that TcCCE06 mediates the enantioselective metabolism of FEN in T. cinnabarinus . Our findings will contribute to a more comprehensive understanding of the mechanisms underlying the differential toxicity of the FEN enantiomers against T. cinnabarinus . Furthermore, they also provide a new perspective for the development of enantiomer‐enriched acaricides with higher activity and lower pesticide dosage and pollution risks. © 2023 Society of Chemical Industry.