A point mutation in the glutamate‐gated chloride channel of Plutella xylostella is associated with resistance to abamectin
A point mutation in the glutamate‐gated chloride channel of Plutella xylostella is associated with resistance to abamectin
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DOI：
10.1111/imb.12204
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发表时间：
2016-04
影响因子：
2.6
通讯作者：
X. Wang;Ran Wang;Y. Yang;S. Wu;A. O’Reilly;Y. Wu
中科院分区：
文献类型：
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作者：
X. Wang;Ran Wang;Y. Yang;S. Wu;A. O’Reilly;Y. Wu
小菜蛾是十字花科蔬菜的全球性害虫。小菜蛾田间种群对阿维菌素的抗性逐渐渗入敏感的Roth品系。所得渐渗菌株Roth‐Abm对阿维菌素的抗性是Roth的11 000倍。在Roth-Abm中鉴定了小菜蛾谷氨酸门控氯离子通道（PxGluCl）第三跨膜螺旋（M3）N末端的A309 V置换。PxGluCl的V309等位基因的频率在Roth-Abm中为94.7%，而在Roth中未检测到这种等位基因。在不进行阿维菌素选择的情况下，将Roth‐Abm亚群保持20代，以产生回复突变株Roth‐Abm‐D。与Roth相比，Roth-Abm-D中的阿维菌素抗性下降至1150倍，V309等位基因频率下降至9.6%。用80 mg/l阿维菌素处理Roth‐Abm‐D菌株后，存活者中的V309等位基因频率增加至55%。这表明PxGluCl中的A309 V突变与Roth-Abm中阿维菌素抗性相对于Roth-Abm-D增加10倍密切相关。同源性建模和自动化配体对接结果表明，A309 V取代变构修饰了阿维菌素结合位点，而不是直接消除关键结合接触。除了PxGluCl的A309 V突变外，还讨论了Roth-Abm对阿维菌素的其他耐药机制。
The diamondback moth, Plutella xylostella, is a global pest of cruciferous vegetables. Abamectin resistance in a field population of P. xylostella was introgressed into the susceptible Roth strain. The resulting introgression strain Roth‐Abm showed 11 000‐fold resistance to abamectin compared with Roth. An A309V substitution at the N‐terminus of the third transmembrane helix (M3) of the glutamate‐gated chloride channel of P. xylostella (PxGluCl) was identified in Roth‐Abm. The frequency of the V309 allele of PxGluCl was 94.7% in Roth‐Abm, whereas no such allele was detected in Roth. A subpopulation of Roth‐Abm was kept without abamectin selection for 20 generations to produce a revertant strain, Roth‐Abm‐D. Abamectin resistance in Roth‐Abm‐D declined to 1150‐fold compared with Roth, with the V309 allele frequency decreased to 9.6%. After treatment of the Roth‐Abm‐D strain with 80 mg/l abamectin the V309 allele frequency in the survivors increased to 55%. This demonstrates that the A309V mutation in PxGluCl is strongly associated with a 10‐fold increase in abamectin resistance in Roth‐Abm relative to Roth‐Abm‐D. Homology modelling and automated ligand docking results suggest that the A309V substitution allosterically modifies the abamectin‐binding site, as opposed to directly eliminating a key binding contact. Other resistance mechanisms to abamectin in Roth‐Abm are discussed besides the A309V mutation of PxGluCl.