2025/05/28 by Feng Zhou, Minghan Sun, P. S. Wang +7 · 1 voice
Agricultural and Biological Sciences · #Entomopathogenic Microorganisms in Pest Control #Mycotoxins in Agriculture and Food #Fungal Plant Pathogen Control
paper · doi:10.1094/pdis-03-25-0632-re
openalex publication_date 2025/05/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Rice bakanae disease (RBD), caused by Fusarium fujikuroi, threatens global rice production. While the phenylpyrrole fungicide fludioxonil shows efficacy against F. fujikuroi, resistance mechanisms remain understudied. The current study found that the fludioxonil sensitivity of 101 F. fujikuroi isolates collected in the rice fields of Xinxiang City in the Henan Province of China ranged from 0.025 to 0.759 μg/ml, with an average EC 50 value of 0.3441 ± 0.1961 μg/ml (standard error). Four highly fludioxonil-resistant F. fujikuroi laboratory mutants were generated by repeated exposure to fludioxonil, and they exhibited enhanced mycelial growth and sporulation but reduced spore germination, pathogenicity, and osmotic stress tolerance, alongside abnormal hyphae. Molecular analysis identified amino acid substitutions in the target protein Ffos-1, notably at residue 672 (A672P/T). These acid amino changes reduced the minimum binding energy in docking models. Ffos-1 expression was significantly (P < 0.05) upregulated in fludioxonil-resistant F. fujikuroi mutants. Meanwhile, cross-resistance analysis revealed a significant (P = 0.0064) correlation between fludioxonil and iprodione but not epoxiconazole, prothioconazole, or carbendazim. However, field monitoring is critical, as baseline shifts could compromise fludioxonil efficacy. These findings highlight Ffos-1’s role in fludioxonil action and resistance, informing integrated strategies to delay resistance spread and improve RBD management.