New resistance mechanism in Helicoverpa armigera threatens transgenic crops expressing Bacillus thuringiensis Cry1Ac toxin
New resistance mechanism in Helicoverpa armigera threatens transgenic crops expressing Bacillus thuringiensis Cry1Ac toxin
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DOI：
10.1128/aem.71.5.2558-2563.2005
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发表时间：
2005-05-01
影响因子：
4.4
通讯作者：
Moores, GD
中科院分区：
文献类型：
--
作者：
Gunning, RV;Dang, HT;Moores, GD
在澳大利亚，棉铃虫Helicoverpa armigera对常规杀虫剂具有长期抗性。转基因棉花（表达苏云金芽孢杆菌毒素Cry1Ac）已经种植用于H.自1996年以来控制了armigera。结果表明，澳大利亚的H.棉铃虫对Cry1Ac毒素产生了抗性（275倍）。约70%的抗性H.棉铃虫幼虫能够在CrylAc转基因棉（Ingard）上存活。抗性表型作为常染色体半显性性状遗传。抗性与酯酶水平升高有关，酯酶水平升高与抗性共分离。采用表面等离子体共振技术和其他生化技术的体外研究表明，抗性菌株酯酶可以结合Cry1Ac原毒素和活化毒素。活体研究表明，饲喂转Cy1Ac基因棉或经Cry1Ac处理的人工饲料的抗Cry1Ac幼虫的酯酶活性低于未饲喂Cry1Ac的幼虫。提出了酯酶螯合CrylAc的抗性机制。
In Australia, the cotton bollworm, Helicoverpa armigera, has a long history of resistance to conventional insecticides. Transgenic cotton (expressing the Bacillus thuringiensis toxin Cry1Ac) has been grown for H. armigera control since 1996. It is demonstrated here that a population of Australian H. armigera has developed resistance to Cry1Ac toxin (275-fold). Some 70% of resistant H. armigera larvae were able to survive on CrylAc transgenic cotton (Ingard) The resistance phenotype is inherited as an autosomal semidominant trait. Resistance was associated with elevated esterase levels, which cosegregated with resistance. In vitro studies employing surface plasmon resonance technology and other biochemical techniques demonstrated that resistant strain esterase could bind to Cry1Ac protoxin and activated toxin. In vivo studies showed that Cry1Ac-resistant larvae fed Cy1Ac transgenic cotton or Cry1Ac-treated artificial diet had lower esterase activity than nonCry1Ac-fed larvae. A resistance mechanism in which esterase sequesters CrylAc is proposed.