Yang Zhiming, Deng Mengqing, Wang Wenxiu, Xiao Tianxiang, Peng Haoxue, Huang Zifan, Lu Kai
Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
Int J Biol Macromol. 2024 Mar;261(Pt 1):129745. doi: 10.1016/j.ijbiomac.2024.129745. Epub 2024 Jan 28.
Efficient detoxification is the key factor for phytophagous insect to adapt to phytochemicals. However, the role of uridine diphosphate (UDP)-glycosyltransferases (UGTs) in insect anti-defense to phytochemical flavone is largely unknown. In this study, 52 UGT genes were identified in Spodoptera litura and they presented evident gene duplication. UGT played a crucial part in larval tolerance to flavone because the enzyme activity and transcriptional level of 77 % UGT members were remarkably upregulated by flavone administration and suppression of UGT enzyme activity and gene expressions significantly increased larval susceptibility to flavone. Bacteria coexpressing UGTs had high survival rates under flavone treatment and flavone was dramatically metabolized by UGT recombinant cells, which indicated the involvement of UGTs in flavone detoxification. What's more, ecdysone pathway was activated by flavone. Topical application of 20-hydroxyecdysone highly upregulated UGT enzyme activity and more than half of UGT expressions. The effects were opposite when ecdysone receptor (EcR) and ultraspiracle (USP)-mediated ecdysone signaling pathway was inhibited. Furtherly, promoter reporter assays of 5 UGT genes showed that their transcription activities were notably increased by cotransfection with EcR and USP. In consequence, this study suggested that UGTs were involved in flavone detoxification and their transcriptional expressions were regulated by ecdysone pathway.
高效解毒是植食性昆虫适应植物化学物质的关键因素。然而，尿苷二磷酸（UDP）-糖基转移酶（UGT）在昆虫对植物化学黄酮的抗防御作用中的作用尚不清楚。在本研究中，在斜纹夜蛾中鉴定出52个UGT基因，它们呈现出明显的基因复制。UGT在幼虫对黄酮的耐受性中起关键作用，因为77%的UGT成员的酶活性和转录水平在给予黄酮后显著上调，而抑制UGT酶活性和基因表达会显著增加幼虫对黄酮的敏感性。共表达UGT的细菌在黄酮处理下具有较高的存活率，并且黄酮被UGT重组细胞大量代谢，这表明UGT参与了黄酮解毒。此外，黄酮激活了蜕皮激素途径。局部应用20-羟基蜕皮激素可高度上调UGT酶活性和超过一半的UGT表达。当蜕皮激素受体（EcR）和超气门蛋白（USP）介导的蜕皮激素信号通路被抑制时，效果相反。此外，对5个UGT基因的启动子报告基因分析表明，与EcR和USP共转染可显著增加它们的转录活性。因此，本研究表明UGT参与黄酮解毒，并且它们的转录表达受蜕皮激素途径调控。
