Abstract：
BACKGROUND: Rice sheath blight caused by Rhizoctonia solani is a severe threat to the yield and quality of rice. Due to the unscientific abuse of common fungicides causing resistance and environmental issues, the development of new fungicides is necessary. In this study, we used citral as the lead compound, designed and synthesized a series of novel citral amide derivatives, and evaluated their antifungal activity and mode of action against R. solani.
RESULTS: Bioassay results indicated that the antifungal activities of most citral amide derivatives against R. solani were significantly improved compared to citral, with EC50 values ranging from 9.50-27.12 mg L-1. Among them, compound d21 containing the N-(pyridin-4-yl)carboxamide group exhibited in vitro and in vivo fungicidal activities, with curative effects at 500 mg L-1 as effectively as the commercial fungicide validamycin·bacillus. Furthermore, d21 prolonged the lag phase of the growth curve of R. solani, reduced the amount of growth, and inhibited sclerotium germination and formation. Mechanistically, d21 deformed the mycelia, increased cell membrane permeability, and inhibited the activities of antioxidant and tricarboxylic acid cycle (TCA)-related enzymes. Metabolome analysis showed the abundance of some energy-related metabolites within R. solani increased, and simultaneously the antifungal substances secreted by itself reduced. Transcriptome analysis showed that most genes encoding ATP-binding cassette (ABC) transporters and peroxisomes upregulated after the treatment of d21 and cell membrane destruction.
CONCLUSIONS: This study indicates that novel citral amide derivatives possess antifungal activity against R. solani and are expected to develop an alternative option for chemical control of rice sheath blight. © 2024 Society of Chemical Industry.
RESULTS: Bioassay results indicated that the antifungal activities of most citral amide derivatives against R. solani were significantly improved compared to citral, with EC50 values ranging from 9.50-27.12 mg L-1. Among them, compound d21 containing the N-(pyridin-4-yl)carboxamide group exhibited in vitro and in vivo fungicidal activities, with curative effects at 500 mg L-1 as effectively as the commercial fungicide validamycin·bacillus. Furthermore, d21 prolonged the lag phase of the growth curve of R. solani, reduced the amount of growth, and inhibited sclerotium germination and formation. Mechanistically, d21 deformed the mycelia, increased cell membrane permeability, and inhibited the activities of antioxidant and tricarboxylic acid cycle (TCA)-related enzymes. Metabolome analysis showed the abundance of some energy-related metabolites within R. solani increased, and simultaneously the antifungal substances secreted by itself reduced. Transcriptome analysis showed that most genes encoding ATP-binding cassette (ABC) transporters and peroxisomes upregulated after the treatment of d21 and cell membrane destruction.
CONCLUSIONS: This study indicates that novel citral amide derivatives possess antifungal activity against R. solani and are expected to develop an alternative option for chemical control of rice sheath blight. © 2024 Society of Chemical Industry.
摘要：
背景：由水稻枯萎病引起的水稻纹枯病严重威胁着水稻的产量和品质。由于不科学地滥用常见的杀菌剂，引起抗药性和环境问题，开发新的杀菌剂是必要的。在这项研究中,我们用柠檬醛作为先导化合物,设计并合成了一系列新型的柠檬醛酰胺衍生物,并评估了它们对R.solani的抗真菌活性和作用方式。
结果：生物测定结果表明，与柠檬醛相比，大多数柠檬酰胺衍生物对solani的抗真菌活性得到了显着提高，EC50值范围为9.50-27.12mg/L。其中,含有N-(吡啶-4-基)甲酰胺基团的化合物d21表现出体外和体内杀菌活性，在500mg/L时的疗效与市售杀菌剂有效的霉素·杆菌一样有效。此外，D21索兰尼生长曲线的延长滞后期，减少了增长量，并抑制菌核的萌发和形成。机械上,d21使菌丝体变形，细胞膜通透性增加，并抑制抗氧化和TCA相关酶的活性。代谢组分析显示，一些能量相关的代谢产物的丰度增加。同时自身分泌的抗真菌物质减少。转录组分析表明，大多数编码ABC转运蛋白和过氧化物酶体的基因在d21和细胞膜破坏后上调。
结论：这项研究表明，新型的柠檬醛酰胺衍生物具有抗水稻纹枯病的抗真菌活性，有望开发一种化学控制水稻纹枯病的替代选择。本文受版权保护。保留所有权利。
结果：生物测定结果表明，与柠檬醛相比，大多数柠檬酰胺衍生物对solani的抗真菌活性得到了显着提高，EC50值范围为9.50-27.12mg/L。其中,含有N-(吡啶-4-基)甲酰胺基团的化合物d21表现出体外和体内杀菌活性，在500mg/L时的疗效与市售杀菌剂有效的霉素·杆菌一样有效。此外，D21索兰尼生长曲线的延长滞后期，减少了增长量，并抑制菌核的萌发和形成。机械上,d21使菌丝体变形，细胞膜通透性增加，并抑制抗氧化和TCA相关酶的活性。代谢组分析显示，一些能量相关的代谢产物的丰度增加。同时自身分泌的抗真菌物质减少。转录组分析表明，大多数编码ABC转运蛋白和过氧化物酶体的基因在d21和细胞膜破坏后上调。
结论：这项研究表明，新型的柠檬醛酰胺衍生物具有抗水稻纹枯病的抗真菌活性，有望开发一种化学控制水稻纹枯病的替代选择。本文受版权保护。保留所有权利。
