Genome-Wide Characterization of ABCG Transporters Involved in Anthranilic Diamide Insecticide Tolerance in Spodoptera exigua (Lepidoptera: Noctuidae)

The beet armyworm, Spodoptera exigua (Hübner), has developed pronounced resistance to nearly all major classes of insecticides, posing a persistent threat to global agricultural productivity. The ATP-binding cassette (ABC) transporters, particularly members of the G subfamily, mediate the transmembrane efflux of xenobiotics and are increasingly implicated in insecticide tolerance, but the functional roles of the ABCG subfamily in S. exigua remain poorly understood. In this study, we identified 17 SeABCG genes and systematically characterized their spatiotemporal expression patterns and insecticide-responsive profiles. Most SeABCGs were broadly expressed across developmental stages and tissues, although with notable quantitative variation. Among the insecticide-responsive candidates, SeABCG3, SeABCG8, and SeABCG10 were significantly upregulated after treatment with cyantraniliprole and chlorantraniliprole and were highly expressed in detoxification tissues; these three genes were therefore selected for functional studies. Functional characterization through RNAi confirmed that SeABCG3, SeABCG8, and SeABCG10 contribute to tolerance against cyantraniliprole and chlorantraniliprole. Furthermore, molecular docking results revealed that SeABCG3, SeABCG8, and SeABCG10 exhibit potential binding affinity for both cyantraniliprole and chlorantraniliprole. These findings provide the first functional characterization of ABCG transporters in S. exigua and identify SeABCGs as crucial factors contributing to tolerance to anthranilic diamide insecticides.