Unlocking Nature’s Microbial Defenders: Genetic Mechanisms and Potential Against Monilinia spp. Pathogens

<i>Monilinia</i> spp., which causes brown rot, is one of the most damaging pathogens in stone fruits. Researchers are exploring epiphytic and endophytic microorganisms with the potential to suppress pathogens, control pathogenic microorganisms, and/or promote plant growth. In this study, microorganisms with antagonistic activity against three <i>Monilinia</i> species were isolated from plum orchard soil and plum fruits. Antagonism tests in vitro showed strong antagonistic properties of six strains of bacteria and two yeast-like fungi against <i>M. fructigena</i>, <i>M. fructicola</i>, and <i>M. laxa</i>, with growth inhibition from 45.5 to 84.6%. The antagonists were identified and characterized at the genetic level using whole genome sequencing (WGS). Genes involved in antibiotic resistance, virulence, secondary metabolite synthesis, and plant growth promotion were identified and characterized through genome mapping, gene prediction, and annotation. None of the microorganisms studied were predicted to be pathogenic to humans. The results of this study indicate that the bacteria <i>Bacillus pumilus</i>, <i>B. velezensis</i>, two strains of <i>Lysinibacillus agricola</i>, <i>Pseudomonas chlororaphis</i> isolated from stone fruit orchard soil, and the yeast-like fungus <i>Aureobasidium pullulans</i>, isolated from plums, are promising candidates for the biological control of <i>Monilinia</i> spp.