NRPS genes provide antifungal activity to new Bacillus and Paenibacillus strains and change their expression in the presence of phytopathogens in a strain-specific manner

Abstract

Fusarium diseases pose a significant threat to agricultural crops. In agricultural practice, various chemical fungicides, typically triazole-based, are often used to control fusariosis. However, this practice contributes to the development of resistant strains among the pathogenic fungi. A potential alternative to chemical fungicide treatments involves utilizing biopreparations derived from natural antagonists of Fusarium. Bacillus and Paenibacillus bacteria, isolated from farmland soils have shown notable antagonistic activity against phytopathogenic Fusarium fungi. Genetic analysis via PCR has indicated the presence of nonribosomal peptide synthase genes in the isolated bacterial strains, with the absence of chitinase activity suggesting that the antifungal effect primarily stems from nonribosomal synthesized peptides. Furthermore, the expression of these genes is heightened in the presence of fungi during co-culturing, although the magnitude of this effect appears to be specific to each strain and dependent on the pathogen in question. Field trials have demonstrated the efficacy of a biocontrol preparation made from studied Bacillus and Paenibacillus strains. These results suggest promising prospects for the development of pathogen-targeted treatments.