College of Plant Science, Jilin University, Changchun 130062, PR China.
Department of Entomology, China Agricultural University, Beijing 100193, PR China.
Pestic Biochem Physiol. 2018 Jun;148:182-189. doi: 10.1016/j.pestbp.2018.04.015. Epub 2018 Apr 27.
The cytochrome P450 monooxygenases play a key role in detoxification mechanism for spirotetramat resistance in Aphis gossypii Glover. However, only one P450 genes (CYP6DA2), among thirty-five P450 genes identified from Aphis gossypii transcriptome database, has been reported to play important role in spirotetramat resistance in previous resistance level until now. In this study, after the confirmation of the rise of resistance level and important roles of P450s in spirotetramat resistance by the synergism analysis, the gene expression changes were determined for P450 genes in spirotetramat susceptible and resistant strains. Compared with the susceptible strain, CYP6CY4, CYP6CY14, CYP6CY18 and CYP6DC1 in CYP3 Clade were up-regulated in resistant nymphs, with the CYP6CY14, CYP6CY4, CYP6DC1, and CYP6CY18 increased to 2.54-, 1.51-, 1.31- and 1.29-fold, respectively. Eight genes in CYP3 Clade, three genes in CYP4 Clade and one gene in Mito Clade were down-regulated. In resistant adult aphids, CYP380C6 in CYP4 Clade, CYP353B1 in CYP2 Clade, and CYP307A1 in Mito Clade were up-regulated under spirotetramat stress, with the CYP380C6, CYP353B1 and CYP307A1 increased to 2.89-, 1.91-, and 1.38-fold, respectively. In contrast, the other P450 genes were almost down-regulated, especially these P450 genes in CYP3 Clade, CYP4 Clade and Mito Clade. RNA interference of CYP380C6 significantly increased the sensitivity of the resistant adults and nymphs to spirotetramat, while suppression of CYP6CY14 could not increase the toxicity of spirotetramat. These results indicate the possible involvement of the CYP380C6 genes in spirotetramat resistance at present very high resistance levels. Screening the expression changes of P450 genes under different spirotetramat resistance levels in the genome-scale will provide an overall view on the possible metabolic factors in the resistance development. The results may facilitate further work to validate the roles of P450 in spirotetramat resistance with heterologous expression.
细胞色素 P450 单加氧酶在棉蚜对螺虫乙酯解毒机制中起着关键作用。然而，在之前的抗性水平研究中，仅鉴定出 35 个棉蚜转录组数据库中的 P450 基因中的一个（CYP6DA2）在螺虫乙酯抗性中起着重要作用。在本研究中，通过协同作用分析确认了抗性水平的提高和 P450 在螺虫乙酯抗性中的重要作用后，确定了敏感和抗性品系中 P450 基因的表达变化。与敏感品系相比，CYP6CY4、CYP6CY14、CYP6CY18 和 CYP6DC1 在 CYP3 类群中在抗性若虫中上调，其中 CYP6CY14、CYP6CY4、CYP6DC1 和 CYP6CY18 分别增加到 2.54、1.51、1.31 和 1.29 倍。CYP3 类群中的 8 个基因、CYP4 类群中的 3 个基因和 Mito 类群中的 1 个基因下调。在抗性成蚜中，CYP380C6 在 CYP4 类群中、CYP353B1 在 CYP2 类群中、CYP307A1 在 Mito 类群中上调，CYP380C6、CYP353B1 和 CYP307A1 分别增加到 2.89、1.91 和 1.38 倍。相比之下，其他 P450 基因几乎下调，尤其是 CYP3 类群、CYP4 类群和 Mito 类群中的这些 P450 基因。CYP380C6 的 RNA 干扰显著提高了抗性成蚜和若虫对螺虫乙酯的敏感性，而 CYP6CY14 的抑制不能增加螺虫乙酯的毒性。这些结果表明 CYP380C6 基因可能参与了目前非常高的抗性水平下的螺虫乙酯抗性。在基因组规模上筛选不同螺虫乙酯抗性水平下 P450 基因的表达变化，将为抗性发展中的可能代谢因素提供全面的认识。这些结果可能有助于进一步用异源表达验证 P450 在螺虫乙酯抗性中的作用。
