Biological control of a novel strain Bacillus velezensis BFWR11 against tomato early blight.

As a globally important vegetable crop, tomato suffers significant yield losses due to early blight, a fungal disease caused by Alternaria solani. This study investigated the antifungal activity and plant growth-promoting effects of a novel strain, Bacillus velezensis BFWR11. Genomic analysis identified gene clusters responsible for synthesizing metabolites, including lipopeptides and cell wall-degrading enzymes. Among these were clusters for ribosomally synthesized and post-translationally modified peptides (RiPPs), a class known for their potent antibacterial properties. Additionally, some key compounds responsible for synthesizing surface activators, flagellin, and other compounds with antifungal properties were identified by LC-MS analysis. The strain also produces plant growth-promoting substances, including indole-3-acetic acid (IAA). A plate confrontation experiment confirmed that the Bacillus velezensis BFWR11 significantly inhibits the growth of mold hyphae, including Alternaria solani, Cercospora sorghi, Rhizoctonia solani, Monilinia fructicola and Fusarium graminearum. Tomato potting experiment revealed that Bacillus velezensis BFWR11 promoted the growth of shoots, roots, and biomass accumulation, enhanced plant stress tolerance and endogenous disease resistance. These findings highlight the potential of B. velezensis BFWR11 as a highly effective biocontrol agent and plant growth promoter in tomato cultivation.