Overexpression of SmUGGT1 Confers Imidacloprid Resistance to Sitobion miscanthi (Takahashi).

Sitobion miscanthi , the main species of wheat aphids, is one kind of harmful pest. Chemical insecticides are the important agrochemical products to effectively control wheat aphids. However, the broad application has led to serious resistance of pests to several insecticides, and understanding insecticide resistance mechanisms is critical for integrated pest management. In this study, SmUGGT1 , a new uridine diphosphate (UDP)-glycosyltransferase ( UGT ) gene, was cloned and more strongly expressed in the SM-R (the resistant strain to imidacloprid) than in the SM-S (the susceptible strain to imidacloprid). The increased susceptibility to imidacloprid was observed after silencing SmUGGT1 , indicating that it can be related to the resistance to imidacloprid. Subsequently, SmUGGT1 regulated post-transcriptionally in the coding sequences (CDs) by miR-81 was verified and involved in the resistance to imidacloprid in S. miscanthi . This finding is crucial in the roles of UGT involved in insecticide resistance management in pests.