赵倩楠 黄明娇 危学高 杨静 杜田华 殷城 向文胜 杨鑫 张友军

摘要 烟粉虱是一种世界性农业害虫，其防治手段以化学防治为主，新烟碱类杀虫剂吡虫啉常年用于防治烟粉虱，田间烟粉虱已经形成严重的抗药性。本研究通过分析烟粉虱吡虫啉抗性和敏感种群，发现细胞色素CYP6EM1基因在吡虫啉抗性品系中上调了4.7倍，进而克隆了其全长基因，进行了荧光定量PCR分析，发现该基因在吡虫啉抗性烟粉虱3龄若虫期和雄虫成虫期过量表达，并且在抗性成虫胸部和腹部过量表达。最后通过RNA干扰的方法使成虫的CYP6EM1基因表达量下降了54.8%，之后发现当烟粉虱暴露于吡虫啉时死亡率显著升高了3965%，这表明CYP6EM1与烟粉虱对吡虫啉抗性的形成相关。研究结果对于揭示烟粉虱对吡虫啉产生抗性的机制有帮助，也为烟粉虱抗性水平田间监测及烟粉虱综合治理提供理论依据。

关键词 烟粉虱; 吡虫啉; 细胞色素P450; RNA干扰

中图分类号： S 481.4

文献标识码： A

DOI： 10.16688/j.zwbh.

2020279

Cloning of cytochrome P450 gene CYP6EM1 and its function in imidacloprid resistance in whitefly， Bemisia tabaci

ZHAO Qiannan1， HUANG Mingjiao2， WEI Xuegao2， YANG Jing2， DU Tianhua2，YIN Cheng2， XIANG Wensheng1， YANG Xin2， ZHANG Youjun1，2*

（1. College of Life Science， Northeast Agricultural University， Harbin 150030， China; 2. Institute of Vegetables

and Flowers， Chinese Academy of Agricultural Sciences， Beijing 100081， China）

Abstract

Whitefly， Bemisia tabaci， is a global harmful pest， and insecticides were widely used to control this pest. Imidacloprid， one of the neonicotinoid insecticides， has been used to control whitefly for many years. However， resistance to imidacloprid has been developed in field strains. In this study， the imidacloprid resistant and susceptible populations were compared， and a cytochrome P450 gene， CYP6EM1 was found to be over-expressed in resistant strain for 4.7 fold. The full length of CYP6EM1 was cloned and the mRNA expression level was analyzed by qRT-PCR. The results showed that CYP6EM1 was over-expressed in the third instar nymph and male adult of B.tabaci of imidacloprid resistance， and abound in thorax and abdomen of resistant adult. Moreover， the expression level of CYP6EM1 gene in adults was reduced by 54.8% by RNA interference. Then， it was found that the mortality of B.tabaci significantly increased by 39.65% when exposed to imidacloprid. This study is conducive to revealing the imidacloprid resistance mechanism of B.tabaci and provides a theoretical significance to determine the status of imidacloprid resistance in B.tabaci in the field and further establish the IPM strategies for whiteflies.

Key words

Bemisia tabaci; imidacloprid; cytochrome P450; RNA interference

烟粉虱Bemisia tabaci是一种世界性园艺害虫，寄主植物广泛，目前已经报道的寄主植物已经超过600多种，具有广泛的植物适应性[1]。烟粉虱为害主要有三种途径：直接吸食植物汁液使得植物生长缓慢，严重时萎蔫;分泌蜜露诱发煤污病影响植物光合作用;传播植物病毒，特别是植物双生病毒，导致大面积植株矮小，结实率降低甚至绝产，造成严重的经济危害[2-4]。

烟粉虱的防治以化学防治为主，由于烟粉虱是一种刺吸性小型蔬菜害虫，主要在植物叶片背部刺吸植物汁液，传统的触杀型杀虫剂很难防治烟粉虱，而具有植物内吸性的新烟碱类杀虫剂是防治烟粉虱等刺吸性害虫的首选药剂，对烟粉虱成虫及若虫均有很好的防效[5]。……