Antifungalmycin N2 (3-methyl-3,5-amino-4-vinyl-2-pyrone, C6H7O2N), was a novel and broad-spectrum antifungal metabolite produced by Streptomyces sp. N2. In the present work, antifungalmycin N2 was evaluated its induction of resistance against Rhizoctonia solani in rice seedling by measuring the defense-related physiological and biochemical parameters, such as the production of reactive oxygen species (ROS), the enzymatic activities involved in antioxidant systems (superoxide dismutase, SOD; catalase, CAT; peroxidase, POD), phenolics metabolism (phenylalanine ammonia-lyase, PAL; polyphenol oxidase, PPO), and pathogenesis-related proteins (β-1,3-glucanase and chitinase). It was found that the percentage disease index (PDI) of the R. solani-inoculated rice reduced from 65.21% to 26.02% when treated with 5.77 μg/ml antifungalmycin N2. Further results showed that the rice seedling could trigger its defense responses to R. solani infection by sharply accelerating the accumulation of ROS such as ·O2¬ and H2O2. But when the R. solani-inoculated rice was treated with antifungalmycin N2, the antioxidant SOD, CAT, and POD were significantly induced during the whole period of post inoculation (24–96 h), and consequently resulted in a sharp decline of ·O2¬ and H2O2 in rice seedlings. Compared with the R. solani-inoculated rice, the enzymatic activities of PPO, PAL, β-1,3-glucanase, and chitinase were significantly enhanced in the rice treated with antifungalmycin N2 plus R. solani. In conclusion, the above results suggested that antifungalmycin N2 could induce the resistance against R. solani in rice seedling by stimulating a series of defense responses, which would provide a comprehensive insight into the biocontrol function beyond its direct antagonistic activity against plant fungal pathogens.

中文翻译：

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来自链霉菌属的新型抗真菌霉素 N2 在水稻幼苗中诱导对立枯丝核菌的防御反应。氮气

Antifungalmycin N2（3-methyl-3,5-amino-4-vinyl-2-pyrone，C6H7O2N）是一种由链霉菌产生的新型广谱抗真菌代谢物。N2。在目前的工作中，通过测量与防御相关的生理和生化参数，如活性氧 (ROS) 的产生、参与抗氧化系统的酶活性，评估了抗真菌霉素 N2 对水稻幼苗抗性的诱导作用。超氧化物歧化酶，SOD；过氧化氢酶，CAT；过氧化物酶，POD），酚类代谢（苯丙氨酸解氨酶，PAL；多酚氧化酶，PPO）和发病相关蛋白（β-1,3-葡聚糖酶和几丁质酶）。结果发现，当用 5.77 μg/ml 抗真菌霉素 N2 处理时，R. solani 接种的水稻的疾病百分比指数 (PDI) 从 65.21% 降低到 26.02%。进一步的结果表明，水稻幼苗可以通过急剧加速·O2¬和H2O2等ROS的积累来触发其对R. solani感染的防御反应。但当R. solani 接种的水稻用抗真菌霉素N2 处理时，抗氧化剂SOD、CAT 和POD 在接种后的整个时间段（24-96 h）都被显着诱导，从而导致·O2 急剧下降。 ¬ 和水稻幼苗中的 H2O2。与接种茄病菌的水稻相比，抗真菌霉素N2和茄病菌处理的水稻中PPO、PAL、β-1,3-葡聚糖酶和几丁质酶的酶活性显着增强。综上所述，上述结果表明，抗真菌霉素 N2 可以通过刺激一系列防御反应来诱导水稻幼苗对 R. solani 的抗性，