Abstract：
BACKGROUND: Fusarium head blight (FHB) caused by Fusarium graminearum species complex (FGSG) remains a major challenge to cereal crops and resistance to key fungicides by the pathogen threatens control efficacy. Pydiflumetofen, a succinate dehydrogenase inhibitor, and phenamacril, a cyanoacrylate fungicide targeting myosin I, have been applied to combat this disease. Nonetheless, emergence of pydiflumetofen resistance in a subset of field isolates alongside laboratory-induced facile generation of phenamacril-resistant isolates signals a critical danger of resistance proliferation.
RESULTS: Our study investigates the development of dual resistance to these fungicides in F. graminearum. Utilizing pydiflumetofen-resistant (PyR) and -sensitive (PyS) isolates, we obtained dual-resistant (PyRPhR) and phenamacril-resistant (PySPhR) mutants on potato sucrose agar containing phenamacril. Mutation rates for phenamacril resistance were comparable between pydiflumetofen-resistant and -sensitive isolates, implying independent pathways for resistance development. The mutants compromised in fungal growth, competitive viability and deoxynivalenol production, suggesting fitness penalties for the dual-resistant mutants. However, no cross-resistance was found with tebuconazole or fludioxonil. In addition, we characterized four critical amino acid changes (S217L, C423R, K537T, E420G) in the Myo1 that were verified to confer phenamacril resistance in F. graminearum.
CONCLUSIONS: This research indicates the possibility of resistance development for both pydiflumetofen and phenamacril in F. graminearum and emphasizes the need for fungicide resistance management for FHB. © 2024 Society of Chemical Industry.
RESULTS: Our study investigates the development of dual resistance to these fungicides in F. graminearum. Utilizing pydiflumetofen-resistant (PyR) and -sensitive (PyS) isolates, we obtained dual-resistant (PyRPhR) and phenamacril-resistant (PySPhR) mutants on potato sucrose agar containing phenamacril. Mutation rates for phenamacril resistance were comparable between pydiflumetofen-resistant and -sensitive isolates, implying independent pathways for resistance development. The mutants compromised in fungal growth, competitive viability and deoxynivalenol production, suggesting fitness penalties for the dual-resistant mutants. However, no cross-resistance was found with tebuconazole or fludioxonil. In addition, we characterized four critical amino acid changes (S217L, C423R, K537T, E420G) in the Myo1 that were verified to confer phenamacril resistance in F. graminearum.
CONCLUSIONS: This research indicates the possibility of resistance development for both pydiflumetofen and phenamacril in F. graminearum and emphasizes the need for fungicide resistance management for FHB. © 2024 Society of Chemical Industry.
摘要：
背景：由镰刀菌物种复合体（FGSG）引起的镰刀菌枯萎病（FHB）仍然是谷类作物的主要挑战，并且病原体对关键杀真菌剂的抗性威胁到控制功效。吡氟丁胺,琥珀酸脱氢酶抑制剂,和非那普利,一种针对肌球蛋白I的氰基丙烯酸酯类杀菌剂,已被用于对抗这种疾病。尽管如此，在现场分离株的一部分中出现吡氟丁胺芬耐药性，同时实验室诱导的耐非那普利分离株的容易产生，预示着耐药性增殖的关键危险。
结果：我们的研究调查了在禾谷草中对这些杀真菌剂的双重抗性的发展。利用吡二氟丁芬抗性（PyR）和敏感（PyS）分离株，我们在含非那普利的马铃薯蔗糖琼脂上获得了双重抗性（PyRPhR）和耐非那普利（PySPhR）突变体。耐双氟丁胺芬耐药和敏感分离株之间的非那莫曲耐药突变率相当，暗示抗性发展的独立途径。突变体在真菌生长中受损，竞争性和脱氧雪腐镰刀菌烯醇生产，建议对双重抗性突变体的适应性惩罚。然而,未发现与戊唑醇或氟dioxonil的交叉耐药。此外,我们表征了四个关键氨基酸变化(S217L，C423R,K537T,E420G）在Myo1中，已证实在禾谷F.中赋予了非那普利抗性。
结论：这项研究表明，在赤霉病菌中，吡氟美芬和非那莫曲都可能产生耐药性，并强调需要对FHB进行杀菌剂耐药性管理。©2024化学工业学会。
结果：我们的研究调查了在禾谷草中对这些杀真菌剂的双重抗性的发展。利用吡二氟丁芬抗性（PyR）和敏感（PyS）分离株，我们在含非那普利的马铃薯蔗糖琼脂上获得了双重抗性（PyRPhR）和耐非那普利（PySPhR）突变体。耐双氟丁胺芬耐药和敏感分离株之间的非那莫曲耐药突变率相当，暗示抗性发展的独立途径。突变体在真菌生长中受损，竞争性和脱氧雪腐镰刀菌烯醇生产，建议对双重抗性突变体的适应性惩罚。然而,未发现与戊唑醇或氟dioxonil的交叉耐药。此外,我们表征了四个关键氨基酸变化(S217L，C423R,K537T,E420G）在Myo1中，已证实在禾谷F.中赋予了非那普利抗性。
结论：这项研究表明，在赤霉病菌中，吡氟美芬和非那莫曲都可能产生耐药性，并强调需要对FHB进行杀菌剂耐药性管理。©2024化学工业学会。
