Identification and functional validation of glutathione S-transferase genes involved in detoxification of sulfoxaflor, afidopyropen and lambda-cyhalothrin in Aphis glycines.
BACKGROUND Glutathione S-transferases (GSTs) play important roles in the detoxification of insecticides in insects. However, genome-wide identification and functional characterization of the GST gene family in the soybean aphid Aphis glycines have not been performed. RESULTS A total of 17 AgGST genes were identified in the A. glycines genome and classified into five classes. Phylogenetic analysis and chromosomal mapping showed that delta and epsilon class genes experienced significant expansion. Exposure to LC₅₀ concentrations of sulfoxaflor, afidopyropen and lambda-cyhalothrin strongly induced several AgGST genes with AgGSTd5, AgGSTd6 and AgGSTe2 displaying the highest expression levels. RNA interference of AgGSTd5 significantly increased aphid mortality following exposure to all three insecticides. Knockdown of AgGSTd6 significantly elevated mortality under sulfoxaflor, while knockdown of AgGSTe2 significantly increased mortality under both sulfoxaflor and lambda-cyhalothrin. In contrast, silencing of AgGSTt1 and AgGSTt2 showed no significant effect on aphid mortality under the tested insecticides. CONCLUSION This study provides comprehensive characterization of the GST gene family in A. glycines and demonstrates that AgGSTd5 plays a central role in the detoxification of sulfoxaflor, afidopyropen and lambda-cyhalothrin, while AgGSTd6 and AgGSTe2 contribute to tolerance against specific insecticides among the three compounds. These genes represent promising molecular targets for monitoring insecticide detoxification responses and for the development of strategies based on GST inhibitors to enhance insecticide efficacy in integrated pest management. © 2026 Society of Chemical Industry.