Outstanding biocontrol and plant growth promotion traits of Pseudomonas fluorescens UM270 and other plant-associated Pseudomonas

Plant-beneficial Pseudomonas spp. is a group of soil bacteria with a broad metabolic and functional repertoire that has been exploited as bioinoculants to enhance crop health and production. Among them, Pseudomonas fluorescens strain UM270 stands out as a biocontrol agent and plant growth promoter, which was isolated from the rhizosphere of Medicago truncatula plants in Morelia, Mexico. Its genome contains genes with direct and indirect beneficial functions for plants, such as the production of siderophores, 2,4-diacetylphloroglucinol, phosphate solubilization, phenazines, cyanogens, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, proteases, indole-3-acetic acid, or antimicrobial volatiles like dimethyl disulfide and dimethylhexadecylamine, among others. Its antagonistic properties have been tested against major fungal pathogens such as Botrytis cinerea, Rhizoctonia solani, Diaporthe phaseolorum, Fusarium spp., and Colletotrichum lindemuthianum. The UM270 strain has been shown to be beneficial (either in greenhouse or open-field conditions) for crops such as maize, common bean, husk tomato, blueberry, tomato and squash. In this review, we analyze the phylogenetic, genomic, functional and ecological interactions traits of the UM270 strain in the context of other Pseudomonas spp. strains, highlighting its potential as a bioinoculant to address the challenges of sustainable agriculture.