CYP6CM1转基因烟草对Q型烟粉虱抗药性的影响

The Effect of CYP6CM1 Transgenic Tobacco on the Resistance of Q-type Bemisia tabaci to Insecticides

细胞色素P450酶系对杀虫剂的代谢作用是大多数昆虫产生抗药性的主要机制，沉默P450基因能否对烟粉虱抗药性产生影响需要进一步研究。本论文将含O型烟粉虱细胞色素P450基因CYP6CMlRNAi表达框架的转基因烟草饲喂烟粉虱，荧光定量PCR检测发现烟粉虱取食转基因烟草后体内CYP6CMl基因表达量显著下降，仅为取食非转基因烟草烟粉虱的19％～38％；通过琼脂保湿浸叶法和单株活体法研究取食转基因烟草烟粉虱对阿维·吡虫啉抗药性的影响，结果发现在接触1g门L阿维·吡虫啉24～72h后，取食转基因烟草的烟粉虱死亡率分别比取食非转基因烟草的烟粉虱死亡率显著升高20％～30％和15％-20％。本研究结果表明，饲喂烟粉虱转CYP6CMlRNAi基因烟草可以显著降低烟粉虱细胞色素P450CYP6CMl基因的表达，并降低烟粉虱对烟碱类杀虫剂阿维·吡虫啉的抗药性，显著提高了杀虫剂防治效果。

Cytochrome P450-mediated insecticidal metabolism is a major role in resistance of insect pests to insecticides, whether a P450 gene silencing in Bemisia tabaci influnces resistance to insecticide needs further study. Through feeding B. tabaci with transgenic tobacco expressing a CYP6CM1-RNAi cassette, qRT-PCR showed that the expression of CYP6CM1 in Bemisia tabaci fed with transgenic tobacco was significantly de- creased, and only accounted for 19%-38% of that fed with non-transgenic tobacco. When exposing to 1 g/L abamectin-imidacloprid for 24-72 h either in the leaf-dip bioassay method or the whole plant bioassay method, the mortality orB. tabaci fed with transgenic tobacco increased 20%-30% and 15%-20%, respectively. These results indicated that transgenic tobacco expressing the CYP6CM1-RNAi cassette significantly interfered the expression of CYP6CM1 gene in B. tabaci, subsequently reduced the insect resistance to abamectin-imidacloprid and signi- ficantlv imorove the control efficiency of the insecticide.