College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
Pestic Biochem Physiol. 2019 Feb;154:23-31. doi: 10.1016/j.pestbp.2018.12.010. Epub 2018 Dec 18.
UDP-glycosyltransferases (UGTs), as phase II detoxification enzymes, are widely distributed within living organisms and play vital roles in the biotransformation of endobiotics and xenobiotics in insects. Insects increase the expression of detoxification enzymes to cope with the stress of xenobiotics, including insecticides. However, the roles of UGTs in insecticide resistance are still seldom reported. In this study, two UGT inhibitors, namely, 5-nitrouracil and sulfinpyrazone, were found to synergistically increase the toxicity of imidacloprid in the resistant population of Diaphorina citri. Based on transcriptome data, a total of 17 putative UGTs were identified. Quantitative real-time PCR showed that fourteen of the 17 UGT genes were overexpressed in the resistant population relative to the susceptible population. Using RNA interference technology to knockdown six UGT genes, the results suggested that silencing the selected UGT375A1, UGT383A1, UGT383B1, and UGT384A1 genes dramatically increased the toxicity of imidacloprid in the resistant population. However, silencing the UGT362B1 and UGT379A1 genes did not result in a significant increase in the toxicity of imidacloprid in the resistant population. These findings revealed that some upregulated UGT genes were involved in imidacloprid resistance in D. citri. These results shed some light upon and further our understanding of the mechanisms of insecticide resistance in insects.
UDP-糖基转移酶（UGTs）作为 II 相解毒酶，广泛分布于生物体内，在昆虫内源性和外源性物质的生物转化中起着至关重要的作用。昆虫通过增加解毒酶的表达来应对包括杀虫剂在内的外源性物质的压力。然而，UGTs 在杀虫剂抗性中的作用仍鲜有报道。在本研究中，发现两种 UGT 抑制剂，即 5-硝基尿嘧啶和磺吡酮，可协同增加噻虫啉在桔小实蝇抗性种群中的毒性。基于转录组数据，共鉴定出 17 个推定的 UGTs。实时定量 PCR 显示，在抗性种群中，17 个 UGT 基因中有 14 个基因的表达量高于敏感种群。利用 RNA 干扰技术敲低 6 个 UGT 基因，结果表明，沉默选定的 UGT375A1、UGT383A1、UGT383B1 和 UGT384A1 基因，可显著增加噻虫啉在抗性种群中的毒性。然而，沉默 UGT362B1 和 UGT379A1 基因不会导致噻虫啉在抗性种群中的毒性显著增加。这些发现表明，一些上调的 UGT 基因参与了桔小实蝇对噻虫啉的抗性。这些结果为我们进一步理解昆虫对杀虫剂的抗性机制提供了一些线索。
