Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, 330045, China.
World J Microbiol Biotechnol. 2019 Sep 6;35(9):145. doi: 10.1007/s11274-019-2720-z.
The various diseases that occur during the growth of plants usually cause a significant reduction in production and quality of agricultural products. Actinomycetes, especially Streptomyces spp., become a valuable biological control resource due to their preponderant abilities to produce various secondary metabolites with novel structure and remarkable biological activity. The present work aimed to isolate an effective antagonistic actinomycete against various soilborne phytopathogenic fungi. By dual culture with Fusarium oxysporum f. sp. niveum, an antagonistic actinomycete named Streptomyces corchorusii stain AUH-1 was screened out from 26 soil samples. The in vitro bioassay results showed that S. corchorusii stain AUH-1 had a broad-spectrum antagonistic activity against a range of fungal plant pathogens, such as F. oxysporum f. sp. niveum, Phytophthora parasitica var. nicotianae, Rhizoctonia solani, P. capsica, Botryosphaeria dothidea, F. oxysporum f. sp. vasinfectum, Verticillium dahliae, and F. oxysporum f. sp. cucumerinum. According to the morphological observations in scanning electron microscopy (SEM) and fluorescence microscope (FM), it was found that the cell membranes of F. oxysporum f. sp. niveum were damaged when treated with the antifungal metabolite form S. corchorusii stain AUH-1. Meanwhile, the dropped ergosterol formation and increased malondialdehyde levels further confirmed that S. corchorusii strain AUH-1 exerted its antagonistic activity against F. oxysporum f. sp. niveum via damaging the structure and function of cell membranes. In conclusion, S. corchorusii strain AUH-1 showed a promising prospect for the development of biological agent, especially due to its broad-spectrum and effective antagonist on various soil-borne plant pathogens.
在植物生长过程中发生的各种病害通常会导致农产品产量和质量显著下降。由于放线菌具有产生各种具有新颖结构和显著生物活性的次生代谢产物的卓越能力，因此它们成为有价值的生物防治资源。本工作旨在分离一种有效拮抗各种土传植物病原菌的放线菌。通过与尖孢镰刀菌（Fusarium oxysporum f. sp. niveum）的双层培养，从 26 个土壤样品中筛选出一种拮抗放线菌，命名为链霉菌（Streptomyces corchorusii）菌株 AUH-1。体外生物测定结果表明，链霉菌（Streptomyces corchorusii）菌株 AUH-1 对一系列真菌植物病原菌具有广谱拮抗活性，如尖孢镰刀菌（F. oxysporum f. sp. niveum）、寄生疫霉（Phytophthora parasitica var. nicotianae）、立枯丝核菌（Rhizoctonia solani）、辣椒疫霉（P. capsica）、地衣镰刀菌（Botryosphaeria dothidea）、尖孢镰刀菌（F. oxysporum f. sp. vasinfectum）、黄萎轮枝菌（Verticillium dahliae）和尖孢镰刀菌（F. oxysporum f. sp. cucumerinum）。通过扫描电子显微镜（SEM）和荧光显微镜（FM）观察形态学发现，当用来自链霉菌（Streptomyces corchorusii）菌株 AUH-1 的抗真菌代谢产物处理时，尖孢镰刀菌（F. oxysporum f. sp. niveum）的细胞膜受损。同时，脱落的麦角固醇形成和增加的丙二醛水平进一步证实，链霉菌（Streptomyces corchorusii）菌株 AUH-1 通过破坏细胞膜的结构和功能发挥其对尖孢镰刀菌（F. oxysporum f. sp. niveum）的拮抗活性。综上所述，链霉菌（Streptomyces corchorusii）菌株 AUH-1 表现出开发生物制剂的广阔前景，特别是由于其对各种土传植物病原菌具有广谱和有效的拮抗作用。
