초록
<P>Gray mold, caused by <I>Botrytis cinerea</I> is a major cause of post-harvest rot of fresh fruits and vegetables. The utilization of selected microorganisms as biocontrol agents is a promising alternative to effectively control gray mold on tomatoes. The current study was conducted to explore potential biocontrol mechanisms of the <I>Pseudomonas</I> strain to control infections on post-harvest tomatoes. Among the 8 tested bacterial isolates, <I>Pseudomonas protegens</I> ML15 demonstrated antagonistic activity to <I>Botrytis cinerea</I>. Moreover, <I>P. protegens</I> ML15 exhibited the production of siderophores, hydrogen cyanide, ammonia, exopolysaccharides, lipase, biosurfactant, 2,4-diacetylphloroglucinol, and several other antifungal compounds, such as 1-tetradecanol, cyclododecane, 2,4-di-tert-butylphenol, and 2-methyl-1-hexadecanol. A comprehensive genomic analysis of <I>P. protegens</I> ML15 unravels 18 distinct genetic regions with the potential for biosynthesizing secondary metabolites, known for their pivotal role in biocontrol responses against plant pathogens. <I>In vivo</I>, experiments showed that both culture suspension and cell-free supernatant of <I>P. protegens</I> ML15 significantly reduced fungal growth (53.0 ± 0.63%) and mitigated disease development (52.8 ± 1.5%) in cherry tomatoes at four days post-<I>B</I>. <I>cinerea</I> inoculation. During the infection, the application of <I>P. protegens</I> ML15 resulted in the augmentation of total antioxidant, phenolic content, and ascorbic acids content. Thus, our results suggested that <I>P. protegens</I> ML15’s role as a biocontrol agent against <I>B. cinerea</I>-induced postharvest tomato decay achieved through the secretion of antifungal substances, induction of tomato defense responses, and inhibition of mycelial growth of <I>B. cinerea</I>. These findings provide a significant contribution to the ongoing search for alternative, eco-friendly methods of controlling gray mold in fresh products. The utilization of <I>P. protegens</I> ML15 as a biocontrol agent could help to reduce the reliance on chemical fungicides and promote sustainable agriculture practices.</P>