Huiwen Tan, X. Hu, Jinghao Hu, Wei Xu, Qianwen Wang, Xiaolan Liu, Lei Guo
INTRODUCTION: UDP-glycosyltransferases (UGTs) are key Phase II detoxification enzymes in insects, playing a crucial role in resistance to a variety of insecticides, including diamides. Cyantraniliprole (CYA) is a systemic diamide insecticide with high toxicity against Bemisia tabaci, a major global agricultural pest transmitting over 200 plant viruses. While B. tabaci has developed medium-level resistance to CYA, the role of UGTs in this resistance remains poorly understood. OBJECTIVES: This study aimed to investigate the role of UGTs in B. tabaci resistance to CYA and further elucidate the underlying mechanisms. METHODS: Synergism bioassays and enzymatic activity analyses were conducted to assess the contribution of UGTs to CYA resistance. RNA sequencing and RT-qPCR were employed to identify differentially expressed BtUGT genes associated with resistance. The functions of UGTs and the UDP-glucose (UDPG) biosynthesis pathway in CYA resistance were confirmed through RNA interference and transgenic Drosophila melanogaster lines. The metabolites of CYA in the resistant strain were identified using LC-MS/MS. A cross-resistance study to chlorantraniliprole was performed to further confirm the role of UGTs in the diamide resistance of B. tabaci. RESULTS: Higher expression of UGTs represents a key metabolic resistance mechanism of B. tabaci to CYA. Specifically, overexpression of BtUGT352B2 and BtUGT352F1, along with the UDP-glucose biosynthesis pathway, contributed significantly to resistance. Four glycoside metabolites of CYA were putatively identified in resistant whiteflies. Significant cross-resistance to chlorantraniliprole confirmed that the UGT-mediated metabolism plays a crucial role in anthranilic diamide resistance in B. tabaci. CONCLUSION: This research advances our understanding of UGT-mediated insecticide resistance mechanisms and provides valuable insights for the development of more sustainable pest management strategies to combat pesticide resistance.