The midgut cadherin-like gene is not associated with resistance to Bacillus thuringiensis toxin Cry1Ac in Plutella xylostella (L.)
The midgut cadherin-like gene is not associated with resistance to Bacillus thuringiensis toxin Cry1Ac in Plutella xylostella (L.)
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DOI：
10.1016/j.jip.2015.01.004
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发表时间：
2015-03-01
影响因子：
3.4
通讯作者：
Zhang, Youjun
中科院分区：
文献类型：
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作者：
Guo, Zhaojiang;Kang, Shi;Zhang, Youjun
革兰氏阳性细菌苏云金芽孢杆菌（Bt）产生Cry毒素，已用于控制重要的农业害虫。目标害虫抗性的演变威胁到这些毒素在喷洒生物农药或Bt转基因作物中使用时的有效性。虽然中肠钙粘蛋白样受体的改变可以导致许多昆虫对Bt Cry毒素产生抗性，但钙粘蛋白基因是否参与了小菜蛾对Cry1Ac的抗性仍不清楚。在这里，我们提出的实验证据表明，抗Cryl Ac或Bt变种。kurstaki（Btk）不是由于cadherin基因的改变。克隆并分析了真正的小菜蛾cadherin cDNA序列，比较了敏感和抗性小菜蛾菌株cadherin cDNA序列，证实了该基因的突变不影响小菜蛾对Cry1Ac的抗性。此外，实时定量PCR（qPCR）表明，钙粘蛋白的转录水平之间没有显着差异敏感和抗性小菜蛾品系。RNA干扰（RNAi）介导的钙粘蛋白基因表达的抑制并不影响幼虫对Cry1Ac毒素的敏感性。此外，使用四种钙粘蛋白gDNA等位基因生物标志物的遗传连锁分析证实，钙粘蛋白基因与小菜蛾对Cry1Ac的抗性无关。综上所述，我们的研究结果表明，小菜蛾的Cry1Ac抗性是独立的钙粘蛋白基因。(C)2015 Elsevier Inc. All rights reserved.
The Gram-positive bacterium Bacillus thuringiensis (Bt) produces Cry toxins that have been used to control important agricultural pests. Evolution of resistance in target pests threatens the effectiveness of these toxins when used either in sprayed biopesticides or in Bt transgenic crops. Although alterations of the midgut cadherin-like receptor can lead to Bt Cry toxin resistance in many insects, whether the cadherin gene is involved in Cry1Ac resistance of Plutella xylostella (L) remains unclear. Here, we present experimental evidence that resistance to Cryl Ac or Bt var. kurstaki (Btk) in P. xylostella is not due to alterations of the cadherin gene. The bona fide P. xylostella cadherin cDNA sequence was cloned and analyzed, and comparisons of the cadherin cDNA sequence among susceptible and resistant P. xylostella strains confirmed that Cry1Ac resistance was independent of mutations in this gene. In addition, real-time quantitative PCR (qPCR) indicated that cadherin transcript levels did not significantly differ among susceptible and resistant P. xylostella strains. RNA interference (RNAi)-mediated suppression of cadherin gene expression did not affect larval susceptibility to Cry1Ac toxin. Furthermore, genetic linkage assays using four cadherin gDNA allelic biomarkers confirmed that the cadherin gene is not linked to resistance against Cry1Ac in P. xylostella. Taken together, our findings demonstrate that Cry1Ac resistance of P. xylostella is independent of the cadherin gene. (C) 2015 Elsevier Inc. All rights reserved.