Li Guixiang, Li Yiwen, Zhang Ling, Jiang Han, Yuan Kang, Miao Jianqiang, Liu Xili
State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Plant Protection, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi, 712100, China.
Department of Plant Pathology, College of Plant Protection, China Agricultural University, 2 Yuanmingyuanxi Road, Beijing, 100193, China.
Stress Biol. 2025 May 1;5(1):30. doi: 10.1007/s44154-025-00221-0.
The fungicide metconazole, which acts as a sterol 14α-demethylation inhibitor (DMI), can exhibit strong inhibitory effects on Fusarium pseudograminearum. However, the resistance mechanism as well as the risk that F. pseudograminearum develops resistance to metconazole is yet to be fully assessed. In this study, metconazole displayed a mean EC value of 0.0559 μg/mL against 105 F. pseudograminearum isolates. Ten sensitive parental isolates were then subjected to fungicide adaptation to generate resistant mutants, with in vitro experiments subsequently highlighting the inferior fitness of the mutants. In addition, metconazole exhibited positive cross-resistance with both mefentrifluconazole and tebuconazole. Altogether, the results confirmed the low risk that F. pseudograminearum develops resistance to metconazole. Finally, a mutation genotype (M151T) was identified in FpCYP51B, with the mutants also overexpressing the FpCYP51 genes. Subsequent molecular docking and transformation-based experiments indicated that M151T substitution and overexpression in FpCYP51 genes conferred resistance to metconazole in F. pseudograminearum.
杀菌剂丙环唑作为一种甾醇14α-脱甲基化抑制剂（DMI），对禾谷镰刀菌具有很强的抑制作用。然而，禾谷镰刀菌对丙环唑的抗性机制以及产生抗性的风险尚未得到充分评估。在本研究中，丙环唑对105株禾谷镰刀菌分离株的平均EC值为0.0559μg/mL。随后，对10株敏感亲本分离株进行杀菌剂适应性处理以产生抗性突变体，体外实验随后突出了突变体适应性较差的特点。此外，丙环唑与联苯三唑醇和戊唑醇均表现出正向交叉抗性。总之，结果证实了禾谷镰刀菌对丙环唑产生抗性的风险较低。最后，在FpCYP51B中鉴定出一种突变基因型（M151T），突变体还过表达FpCYP51基因。随后基于分子对接和转化的实验表明，FpCYP51基因中的M151T取代和过表达赋予了禾谷镰刀菌对丙环唑的抗性。
