Etebari K, Afrad M H, Tang B, Silva R, Furlong M J, Asgari S
School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia.
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and Fujian Provincial Key Laboratory of Insect Ecology, Department of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China.
Insect Mol Biol. 2018 Aug;27(4):478-491. doi: 10.1111/imb.12387. Epub 2018 Mar 24.
The diamondback moth, Plutella xylostella, has developed extremely high levels of resistance to chlorantraniliprole and other classes of insecticides in the field. As microRNAs (miRNAs) play important roles in various biological processes through gene regulation, we examined the miRNA profile of P. xylostella in response to chlorantraniliprole exposure. RNA sequencing analysis showed that insecticide treatment caused significant changes in the abundance of some miRNAs. Increasing exposure time and insecticide concentration induced more dysregulated miRNAs in P. xylostella larvae. We also screened potential target genes for some of the differentially expressed miRNAs (such as miR-2b-3p, miR-14b-5p and let-7-5p), which may play important roles in insecticide resistance development. Exposure of P. xylostella larvae to chlorantraniliprole caused considerable overexpression in the transcript levels of potential target genes cytochrome P450 9f2 (CYP9F2) and 307a1 (CYP307a1). Application of miR-2b-3p and miR-14b-5p mimics significantly suppressed the relative transcript levels of CYP9F2 and CYP307a1, respectively, in a P. xylostella cell line. Furthermore, enrichment of P. xylostella diet with miR-2b-3p mimics significantly increased mortality in deltamethrin-resistant larvae when exposed to deltamethrin. The results suggest that miR-2b-3p may suppress CYP9F2 transcript levels in P. xylostella and consequently inhibit larval detoxification pathways. The findings provide an insight into possible role of miRNAs in regulation of metabolic resistance of insects to insecticides.
小菜蛾（Plutella xylostella）在田间已对氯虫苯甲酰胺和其他种类的杀虫剂产生了极高水平的抗性。由于微小RNA（miRNA）通过基因调控在各种生物学过程中发挥重要作用，我们检测了小菜蛾在接触氯虫苯甲酰胺后的miRNA谱。RNA测序分析表明，杀虫剂处理导致一些miRNA的丰度发生显著变化。延长接触时间和增加杀虫剂浓度会诱导小菜蛾幼虫中更多的miRNA表达失调。我们还筛选了一些差异表达miRNA（如miR-2b-3p、miR-14b-5p和let-7-5p）的潜在靶基因，这些基因可能在抗药性发展中发挥重要作用。小菜蛾幼虫接触氯虫苯甲酰胺会导致潜在靶基因细胞色素P450 9f2（CYP9F2）和307a1（CYP307a1）的转录水平显著上调。在小菜蛾细胞系中分别应用miR-2b-3p和miR-14b-5p模拟物可显著抑制CYP9F2和CYP307a1的相对转录水平。此外，用miR-2b-3p模拟物富集小菜蛾的食物，可显著增加抗溴氰菊酯幼虫在接触溴氰菊酯时的死亡率。结果表明，miR-2b-3p可能会抑制小菜蛾中CYP9F2的转录水平，从而抑制幼虫的解毒途径。这些发现为miRNA在调控昆虫对杀虫剂的代谢抗性中的可能作用提供了见解。
