Department of Entomology, University of Kentucky, Lexington, KY 40546-0091, USA.
Department of Entomology, University of Kentucky, Lexington, KY 40546-0091, USA; Faculty of Forestry and Wood Sciences, EXTEMIT-K, Czech University of Life Sciences, Kamýcká 1176, Prague 6, Suchdol, 165 21, Czech Republic.
Insect Biochem Mol Biol. 2018 Aug;99:54-62. doi: 10.1016/j.ibmb.2018.05.006. Epub 2018 May 28.
The Colorado potato beetle (CPB), Leptinotarsa decemlineata developed resistance to imidacloprid after exposure to this insecticide for multiple generations. Our previous studies showed that xenobiotic transcription factor, cap 'n' collar isoform C (CncC) regulates the expression of multiple cytochrome P450 genes, which play essential roles in resistance to plant allelochemicals and insecticides. In this study, we sought to obtain a comprehensive picture of the genes regulated by CncC in imidacloprid-resistant CPB. We performed sequencing of RNA isolated from imidacloprid-resistant CPB treated with dsRNA targeting CncC or gene coding for green fluorescent protein (control). Comparative transcriptome analysis showed that CncC regulated the expression of 1798 genes, out of which 1499 genes were downregulated in CncC knockdown beetles. Interestingly, expression of 79% of imidacloprid induced P450 genes requires CncC. We performed quantitative real-time PCR to verify the reduction in the expression of 20 genes including those coding for detoxification enzymes (P450s, glutathione S-transferases, and esterases) and ABC transporters. The genes coding for ABC transporters are induced in insecticide resistant CPB and require CncC for their expression. Knockdown of genes coding for ABC transporters simultaneously or individually caused an increase in imidacloprid-induced mortality in resistant beetles confirming their contribution to insecticide resistance. These studies identified CncC as a transcription factor involved in regulation of genes responsible for imidacloprid resistance. Small molecule inhibitors of CncC or suppression of CncC by RNAi could provide effective synergists for pest control or management of insecticide resistance.
科罗拉多马铃薯甲虫（CPB）在接触拟除虫菊酯杀虫剂多代后对其产生了抗性。我们之前的研究表明，外源性生物转化因子，cap 'n' collar 同型异构体 C（CncC）调节多种细胞色素 P450 基因的表达，这些基因在抵抗植物化感物质和杀虫剂方面发挥着重要作用。在这项研究中，我们试图获得 CncC 调节抗拟除虫菊酯 CPB 中基因表达的综合图谱。我们对用靶向 CncC 的 dsRNA 或编码绿色荧光蛋白（对照）的基因处理的抗拟除虫菊酯 CPB 中分离的 RNA 进行测序。比较转录组分析表明，CncC 调节了 1798 个基因的表达，其中 1499 个基因在 CncC 敲低的甲虫中下调。有趣的是，79%的拟除虫菊酯诱导的 P450 基因的表达需要 CncC。我们进行了定量实时 PCR 验证，结果表明 20 个基因（包括解毒酶（P450s、谷胱甘肽 S-转移酶和酯酶）和 ABC 转运蛋白）的表达减少。在抗杀虫剂 CPB 中，编码 ABC 转运蛋白的基因被诱导，并需要 CncC 进行表达。同时或单独敲低编码 ABC 转运蛋白的基因会导致抗性甲虫中拟除虫菊酯诱导的死亡率增加，证实它们对抗虫剂抗性的贡献。这些研究确定 CncC 是一种参与调节与抗拟除虫菊酯相关的基因表达的转录因子。CncC 的小分子抑制剂或 RNAi 抑制 CncC 可能为害虫防治或管理杀虫剂抗性提供有效的协同作用。
