Uridine Diphosphate-Glycosyltransferase RpUGT344D38 Contributes to λ-Cyhalothrin Resistance in Rhopalosiphum padi .

Uridine diphosphate-glycosyltransferase (UGT) is a key phase II enzyme in the insect detoxification system. Pyrethroids are commonly used to control the destructive wheat aphid Rhopalosiphum padi . In this study, we found a highly expressed UGT gene, RpUGT 344 D 38, in both λ-cyhalothrin (LCR)- and bifenthrin (BTR)-resistant strains of R. padi . After exposure to λ-cyhalothrin and bifenthrin, the expression levels of RpUGT 344 D 38 were significantly increased in the resistant strains. Knockdown of RpUGT 344 D 38 did not affect the resistance of BTR, but it did significantly increase the susceptibility of LCR aphids to λ-cyhalothrin. Molecular docking analysis demonstrated that RpUGT344D38 had a stable binding interaction with both bifenthrin and λ-cyhalothrin. The recombinant RpUGT344D38 was able to metabolize 50% of λ-cyhalothrin. This study provides a comprehensive analysis of the role of RpUGT 344 D 38 in the resistance of R. padi to bifenthrin and λ-cyhalothrin, contributing to a better understanding of aphid resistance to pyrethroids.