College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
J Agric Food Chem. 2024 Nov 20;72(46):25522-25532. doi: 10.1021/acs.jafc.4c06858. Epub 2024 Nov 4.
Fusarium head blight (FHB), caused by , severely impacts global wheat production, reducing both the yield and quality. In China, fludioxonil, a phenylpyrrole fungicide, is used for managing FHB. This study assessed fludioxonil activity against 120 strains collected from Hubei, Zhejiang, and Jiangsu in 2024, revealing an average EC value of 0.0273 ± 0.0062 μg/mL. We obtained two resistant mutants through chemical taming and discovered a novel point mutation of FgOs1-M460I. Site-directed mutagenesis confirmed that the FgOs1-M460I mutation greatly reduced fludioxonil sensitivity, with an EC value greater than 100 μg/mL. These mutants also displayed reduced sexual and asexual reproduction and lower virulence and accumulated less glycerol under fludioxonil and osmotic stress compared to sensitive strain. The resistant mutants showed no cross-resistance with carbendazim, tebuconazole, phenamacril, pyraclostrobin, or pydiflumetofen. Thus, we conclude that the FgOs1-M460I substitution regulates fludioxonil resistance and plays a role in asexual reproduction, sexual reproduction, and pathogenicity.
镰刀菌顶腐病（FHB）由 引起，严重影响全球小麦产量，降低产量和质量。在中国，氟唑菌苯胺，一种苯并吡咯类杀菌剂，用于防治 FHB。本研究评估了氟唑菌苯胺对 2024 年从湖北、浙江和江苏采集的 120 株菌株的活性，发现平均 EC 值为 0.0273±0.0062μg/mL。我们通过化学驯化获得了两个抗性突变体，并发现了 FgOs1-M460I 的一个新的点突变。定点突变证实，FgOs1-M460I 突变极大地降低了氟唑菌苯胺的敏感性，EC 值大于 100μg/mL。与敏感菌株相比，这些突变体的有性和无性繁殖能力降低，在氟唑菌苯胺和渗透胁迫下甘油积累减少，毒力降低。抗性突变体与多菌灵、戊唑醇、苯并甲环唑、吡唑醚菌酯或吡氟酰草胺无交叉抗性。因此，我们得出结论，FgOs1-M460I 取代调节氟唑菌苯胺抗性，并在无性繁殖、有性繁殖和致病性中发挥作用。
