Oligomycin-producing Streptomyces newly isolated from Swiss soils efficiently protect Arabidopsis thaliana against Botrytis cinerea

The aim of this project was to identify Streptomyces strains demonstrating antagonistic activity against the necrotrophic phytopathogen Botrytis cinerea, thereby contributing to the pursuit of environmentally friendly methods for plant protection. Fifteen Actinomycete strains were isolated from nine different Swiss soils. Among them, three Streptomyces isolates exhibited strong inhibitory activity against B. cinerea spore germination and mycelial growth in in vitro assays. Moreover, the filtrates of these strains protected Arabidopsis thaliana leaves from this pathogen. The genomes of these three strains were sequenced to investigate the molecular determinants underlying their antagonistic activity against Botrytis cinerea.