AUTHOR=Zhou Lu , Song Chunxu , Muñoz Claudia Y. , Kuipers Oscar P. 

TITLE=Bacillus cabrialesii BH5 Protects Tomato Plants Against Botrytis cinerea by Production of Specific Antifungal Compounds

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.707609

DOI=10.3389/fmicb.2021.707609

ISSN=1664-302X

ABSTRACT=<p>The gray mold caused by the phytopathogen <italic>Botrytis cinerea</italic> presents a threat to global food security. For the biological regulation of several plant diseases, <italic>Bacillus</italic> species have been extensively studied. In this work, we explore the ability of a bacterial strain, <italic>Bacillus cabrialesii</italic> BH5, that was isolated from tomato rhizosphere soil, to control the fungal pathogen <italic>B. cinerea</italic>. Strain <italic>B. cabrialesii</italic> BH5 showed a strong antifungal activity against <italic>B. cinerea</italic>. A compound was isolated and identified as a cyclic lipopeptide of the fengycin family by high-performance liquid chromatography and tandem mass spectrometry (ESI-MS/MS) that we named fengycin H. The fengycin H-treated hyphae of <italic>B. cinerea</italic> displayed stronger red fluorescence than the control, which is clearly indicating that fengycin H triggered the hyphal cell membrane defects. Moreover, root inoculation of tomato seedlings with BH5 effectively promoted the growth of tomato plants. Transcription analysis revealed that both BH5 and fengycin H stimulate induced systemic resistance of tomato plants <italic>via</italic> the jasmonic acid signaling pathway and provide a strong biocontrol effect <italic>in vivo</italic>. Therefore, the strain BH5 and fengycin H are very promising candidates for biological control of <italic>B. cinerea</italic> and the associated gray mold.</p>