Differential alteration of two aminopeptidases N associated with resistance to Bacillus thuringiensis toxin Cry1Ac in cabbage looper
Differential alteration of two aminopeptidases N associated with resistance to Bacillus thuringiensis toxin Cry1Ac in cabbage looper
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DOI：
10.1073/pnas.1102555108
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发表时间：
2011-08-23
影响因子：
11.1
通讯作者：
Wang, Ping
中科院分区：
文献类型：
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作者：
Tiewsiri, Kasorn;Wang, Ping
土壤细菌苏云金芽孢杆菌（Bacillus thuringiensis，Bt）是农业上应用最成功的生物农药，其杀虫蛋白基因是转基因作物中用于防治昆虫的主要转基因。然而，昆虫对Bt毒素抗性的进化威胁着Bt应用的长期未来。到目前为止，在农业环境中已经报告了六种昆虫对Bt毒素产生抗药性的情况，但这些抗药性的分子基础仍然不清楚。在这里，我们报告的抗性Bt毒素Cry1Ac的甘蓝尺蠖，粉纹夜蛾，在温室中进化，与差异改变两个中肠氨肽酶N，APN 1和APN 6，赋予的反式调节机制。生化、蛋白质组和分子生物学分析表明，在Cry1Ac抗性T. ni，APN1显著下调，而APN6显著上调。Cry1Ac抗性与APN1的下调相关，而与APN6的上调无关。APN6和APN1的同时上调和下调可能在补偿APN1的损失以最小化抗性的适合度成本方面发挥作用。沿着鉴定APN1表达减少作为在农业环境中选择Bt抗性的分子基础，我们的研究结果表明APN1对Bt毒素Cry1Ac的作用模式的重要性。
The soil bacterium Bacillus thuringiensis (Bt) is the most successfully used biopesticide in agriculture, and its insecticidal protein genes are the primary transgenes used for insect control in transgenic crops. However, evolution of insect resistance to Bt toxins threatens the long-term future of Bt applications. To date, cases of resistance to Bt toxins have been reported in agricultural situations in six insect species, but the molecular basis for these cases of resistance remains unclear. Here we report that the resistance to the Bt toxin Cry1Ac in the cabbage looper, Trichoplusia ni, evolved in greenhouses, is associated with differential alteration of two midgut aminopeptidases N, APN1 and APN6, conferred by a trans-regulatory mechanism. Biochemical, proteomic, and molecular analyses showed that in the Cry1Ac-resistant T. ni, APN1 was significantly down-regulated, whereas APN6 was significantly up-regulated. The Cry1Ac resistance was correlated with down-regulation of APN1 but not with the up-regulation of APN6. The concurrent up-regulation of APN6 and down-regulation of APN1 might play a role in compensating for the loss of APN1 to minimize the fitness costs of the resistance. Along with identifying reduced expression of APN1 as the molecular basis of Bt resistance selected in an agricultural setting, our findings demonstrate the importance of APN1 to the mode of action of Bt toxin Cry1Ac.