Membrane vesicles associated antimicrobial peptides from PGPR Priestia megaterium VIT-2021 confer in silico efficacy against Pseudomonas syringae virulence protein

Plants encounter multiple physiological and environmental constraints that hinder increased productivity. Among the protective factors, plant growth-promoting rhizobacteria (PGPR) plays a critical role in enhancing plant resilience through diverse mechanisms. Bacterial vesicles have been demonstrated to elicit a broad spectrum of immune responses, however, their application in plants has been relatively underexplored, and most research has focused predominantly on their immune modulatory properties. Vesicles derived from PGPR are particularly promising, as these vesicles carry immune stimulants and other bioactive molecules reflective of the parent bacterium. This research demonstrated that antimicrobial peptides (AMPs) present within the membrane vesicles (MV) of Priestia megaterium VIT-2021 contribute to resistance against the phytopathogen Pseudomonas syringae through an in silico approach. Molecular docking analysis revealed that these AMPs exhibit strong interactions with virulence-associated proteins of P. syringae, including avirulence protein (avrE), hrp outer protein (hopA1), hypersensitive response and pathogenicity protein (hrpS), ice nucleation protein (ina) and syringomycin. The highest binding affinities observed in the docking simulations were further validated through molecular dynamics simulations, which confirmed stable interactions between the AMPs and virulence-associated proteins. Building upon earlier findings demonstrating the inhibitory effect of P. megaterium VIT-2021 MVs against P. syringae, this in silico approach further establishes that AMPs derived from P. megaterium MVs possess significant antimicrobial potential against virulence proteins of P. syringae.