Bacillus velezensis 7-A as a Biocontrol Agent Against Fusarium verticillioides, the Causal Agent of Rice Sheath Rot Disease

作者：Boyu Liu, Qunying Qin, Jian Hu, Jiayi Wang, Juan Gan, Ye Zhuang, Zhengxiang Sun, Yi Zhou · 发表于：Microorganisms · 年份：2025 · DOI：10.3390/microorganisms13112511 · 被引用次数：4 · 研究领域：Plant-Microbe Interactions and Immunity、Microbial Metabolism and Applications、Microbial Natural Products and Biosynthesis

Rice sheath rot has progressively developed into a growing threat to global rice production, particularly in intensively managed systems conducive to disease development. Therefore, accurate identification of the causal pathogen and the development of sustainable management strategies represent urgent scientific requirements. In this study, we isolated the causal organism of rice sheath rot from infected rice tissues and identified it as Fusarium verticillioides based on multi-locus sequence analysis. Eight endophytic bacterial strains were recovered from healthy rice root systems. Among the isolates, Bacillus velezensis isolate 7-A exhibited the strongest antifungal activity against F. verticillioides. This isolate demonstrated broad-spectrum antifungal activity, with inhibition rates ranging from 54.8% to 71.8%. Phylogenetic analysis based on 16S rRNA and gyrB gene sequences identified it as B. velezensis. Further characterization revealed that B. velezensis 7-A is capable of secreting proteases and synthesizing siderophores. The filtered liquid from sterile fermentation markedly inhibited the growth of mycelium in F. verticillioides and induced marked morphological abnormalities. Liquid LC-MS analysis identified multiple antifungal active substances, including camphor, ginkgolides B, salicin, cinnamic acid, hydroxygenkwanin, stearamide, β-carotene, and others. A pot experiment demonstrated that the fermentation broth of B. velezensis 7-A effectively suppressed the occurren...