M233I Mutation in the β-Tubulin of Botrytis cinerea Confers Resistance to Zoxamide.
M233I Mutation in the β-Tubulin of Botrytis cinerea Confers Resistance to Zoxamide.
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DOI：
10.1038/srep16881
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发表时间：
2015-11-24
影响因子：
4.6
通讯作者：
Liu XL
中科院分区：
文献类型：
--
作者：
Cai M;Lin D;Chen L;Bi Y;Xiao L;Liu XL
在161个灰霉病菌田间分离物中检测到3种表型，包括ZoxSCarS(对唑草胺和多菌灵敏感)、ZoxSCarR(对唑草胺和多菌灵敏感)和ZoxRCarR(对唑草胺和多菌灵抗性)，但不包括ZoxRCarS(对唑草胺和多菌灵敏感)。获得2株抗性系数分别为13.28和20.43的稳定菌株，菌丝生长速度、产孢量、致病力和菌核产量均有不同程度的适合度下降。结果表明，在未使用苯并咪唑的情况下，番茄灰霉病菌对唑草胺的抗性风险较低。在ZoxSCarR、ZoxRCarR和ZoxRCarS的β微管蛋白中分别检测到E198V、E198K和M233I。分子对接表明β-微管蛋白第198位是佐沙胺和多菌灵的靶标。第198位突变阻止了β-微管蛋白与多菌灵(E198V/K)形成氢键，并改变了佐沙胺结合口袋(E198K)的构象。M233I对多菌灵的结合没有影响，但导致唑沙胺与F200之间的氢键丧失。M233可能是佐沙胺的唯一靶点，在β微管蛋白的功能中发挥着重要作用。
Three phenotypes were detected in 161 Botrytis cinerea field isolates, including ZoxSCarS (sensitive to zoxamide and carbendazim), ZoxSCarR (sensitive to zoxamide and resistant to carbendazim), and ZoxRCarR (resistant to zoxamide and carbendazim), but not ZoxRCarS (resistant to zoxamide and sensitive to carbendazim). The baseline sensitivity to zoxamide was determined with a mean EC50 of 0.76 μg/ml. Two stable ZoxRCarS isolates were obtained with a resistance factor of 13.28 and 20.43; there was a fitness penalty in mycelial growth rate, sporulation, virulence and sclerotium production. The results suggest that the resistance risk of B. cinerea to zoxamide is low where benzimidazoles have not been used. E198V, E198K and M233I, were detected in the β-tubulin of ZoxSCarR, ZoxRCarR, ZoxRCarS, respectively. Molecular docking indicated that position 198 in β-tubulin were targets for both zoxamide and carbendazim. The mutations at 198 prevented formation of hydrogen bonds between β-tubulin and carbendazim (E198V/K), and changed the conformation of the binding pocket of zoxamide (E198K). M233I had no effect on the binding of carbendazim but resulted in loss of a hydrogen bond between zoxamide and F200. M233 is suggested to be a unique target site for zoxamide and be very important in the function of β tubulin.