College of Plant Protection, Henan Agricultural University, Zhengzhou, China.
Henan Key Laboratory of Creation and Application of New Pesticide, Henan Agricultural University, Zhengzhou, China.
Pest Manag Sci. 2024 Aug;80(8):3979-3987. doi: 10.1002/ps.8101. Epub 2024 Apr 5.
Sclerotium rolfsii is a destructive soil-borne fungal pathogen which is distributed worldwide. In previous study, the succinate dehydrogenase inhibitor (SDHI) fungicide benzovindiflupyr has been identified for its great antifungal activity against Sclerotium rolfsii. This study is aimed to investigate the resistance risk and mechanism of benzovindiflupyr in Sclerotium rolfsii.
Eight stable benzovindiflupyr-resistant isolates were generated by fungicide adaptation. Although the obtained eight resistant isolates have a stronger pathogenicity than the parental sensitive isolate, they have a fitness penalty in the mycelial growth and sclerotia formation compared to the parental isolate. A positive cross-resistance existed in the resistant isolates between benzovindiflupyr and thifluzamide, carboxin, boscalid and isopyrazam. Three-point mutations, including SdhB, SdhC and SdhD, were identified in the benzovindiflupyr-resistant isolates. However, molecular docking analysis indicated that only SdhD could influence the sensitivity of Sclerotium rolfsii to benzovindiflupyr. After mycelial co-incubation of resistant isolates and the sensitive isolate, resistance genes may be transmitted to the sensitive isolate. The in vivo efficacy of benzovindiflupyr and thifluzamide against benzovindiflupyr-resistant isolates was a little lower than that against the sensitive isolate but with no significant difference.
The results suggested a low to medium resistance risk of Sclerotium rolfsii to benzovindiflupyr. However, once resistance occurs, it is possible to spread in the population of Sclerotium rolfsii. This study is helpful to understanding the risk and mechanism of resistance to benzovindiflupyr in multinucleate pathogens such as Sclerotium rolfsii. © 2024 Society of Chemical Industry.
齐整小核菌是一种具有破坏性的土传真菌病原体，分布于世界各地。在之前的研究中，琥珀酸脱氢酶抑制剂（SDHI）杀菌剂苯并维地氟pyr 因其对齐整小核菌具有很强的抗真菌活性而被鉴定。本研究旨在研究苯并维地氟 pyr 在齐整小核菌中的抗药性风险和机制。
通过杀菌剂适应性，产生了 8 株稳定的苯并维地氟 pyr 抗性分离株。虽然获得的 8 株抗性分离株的致病性比亲本敏感分离株强，但与亲本分离株相比，它们在菌丝生长和菌核形成方面存在适应性代价。抗性分离株之间存在苯并维地氟 pyr 与噻氟菌胺、羧菌胺、肟菌酯和异噁唑菌胺之间的正向交叉抗性。在苯并维地氟 pyr 抗性分离株中鉴定出 SdhB、SdhC 和 SdhD 三个点突变。然而，分子对接分析表明，只有 SdhD 可以影响齐整小核菌对苯并维地氟 pyr 的敏感性。在抗性分离株和敏感分离株的菌丝共培养后，抗性基因可能会传递给敏感分离株。苯并维地氟 pyr 和噻氟菌胺对苯并维地氟 pyr 抗性分离株的体内药效略低于对敏感分离株，但无显著差异。
结果表明，齐整小核菌对苯并维地氟 pyr 的抗药性风险为低到中等。然而，一旦发生抗性，它有可能在齐整小核菌种群中传播。本研究有助于了解齐整小核菌等多核病原体对苯并维地氟 pyr 抗性的风险和机制。© 2024 化学工业协会。
