BACKGROUNDGlutathione S‐transferase (GST) is a key phase II detoxification enzyme involved in xenobiotics metabolism, and plays a pivotal role in the evolution of resistance to various types of insecticides. However, the specific functions of GST genes in clothianidin resistance remain obscure in Bradysia odoriphaga.RESULTSHere, a specific GST inhibitor, diethyl maleate (DEM), significantly increased the mortality of Bradysia odoriphaga larvae following exposure to clothianidin, and the activity of GST enzyme in clothianidin‐resistant (CL‐R) strain of Bradysia odoriphaga was markedly greater than that in the SS strain. Two sigma BoGSTs (BoGSTs1 and BoGSTs2) were markedly overexpressed in the CL‐R strain and exhibited a higher abundance in the Malpighian tubules or midgut. Exposure to clothianidin resulted in a significant increased expression of BoGSTs1 and BoGSTs2. The knockdown of BoGSTs1 and BoGSTs2 increased sensitivity of larvae to clothianidin in the resistant strain. Furthermore, overexpression of BoGSTs1 and BoGSTs2 led to a significant increase in Escherichia coli cells tolerance to clothianidin. In vitro metabolic assays indicate that these two GSTs cannot directly metabolize clothianidin and its secondary metabolite desmethyl‐clothianidin. Disk diffusion assays and fluorescence competitive binding assays indicated that BoGSTs1 and BoGSTs2 play a critical role in clothianidin resistance by antioxidant activity and non‐catalytic binding activity. The docking results showed that BoGSTs1 and BoGSTs2 have strong binding affinity toward clothianidin.CONCLUSIONCollectively, these findings pinpoint the potential role of BoGSTs1 and BoGSTs2 in conferring insecticide resistance in Bradysia odoriphaga and contribute to our understanding of the underlying mechanisms of insecticide resistance. © 2024 Society of Chemical Industry.

中文翻译：

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参与 Bradysia odoriphaga 噻虫胺耐药的两个谷胱甘肽 S-转移酶基因的表征


背景Glutathione S-转移酶 （GST） 是参与外源性代谢的关键 II 期解毒酶，在对各种杀虫剂的抗性进化中起关键作用。然而，GST 基因在噻虫胺抗性中的特异性功能在 Bradysia odoriphaga 中仍然不清楚。结果特异性 GST 抑制剂马来酸二乙酯 （DEM） 显着增加了暴露于噻虫胺后 Bradysia odoriphaga 幼虫的死亡率，并且 Bradysia odoriphaga 的噻虫素抗性 （CL-R） 菌株中 GST 酶的活性明显高于 SS 菌株。两个 sigma BoGSTs （BoGSTs1 和 BoGSTs2） 在 CL-R 菌株中显著过表达，并且在 Malpighian 小管或中肠中表现出更高的丰度。暴露于噻虫胺导致 BoGSTs1 和 BoGSTs2 的表达显著增加。BoGSTs1 和 BoGSTs2 的敲除增加了幼虫对抗性菌株中噻虫胺的敏感性。此外，BoGSTs1 和 BoGSTs2 的过表达导致大肠杆菌细胞对噻虫胺的耐受性显着增加。体外代谢测定表明，这两种 GST 不能直接代谢噻虫胺及其次生代谢物去甲基噻虫胺。纸片扩散测定和荧光竞争结合测定表明，BoGSTs1 和 BoGSTs2 通过抗氧化活性和非催化结合活性在噻虫胺抗性中发挥关键作用。对接结果显示，BoGSTs1 和 BoGSTs2 对噻虫胺具有很强的结合亲和力。结论从总体上讲，这些发现确定了 BoGSTs1 和 BoGSTs2 在赋予 Bradysia odoriphaga 杀虫剂抗性方面的潜在作用，并有助于我们了解杀虫剂抗性的潜在机制。© 2024 化工学会.