What does the published scientific research say about Pseudomonas fluorescens?

Eight PubMed-indexed papers cite Pseudomonas fluorescens in plant-input contexts, spanning biocontrol, plant growth promotion, drought tolerance, and rhizosphere microbiome dynamics across tomato, cucumber, soybean, and legume systems.

Reported in peer-reviewed research, P. fluorescens strains produce siderophores, chitinase, and lipopeptides associated with pathogen suppression. Strain NK4 siderophore is reported to show biocontrol activity against Pseudomonas viridiflava in cucumber, while chitinase from strain MP-13 achieved 100% in-vitro mortality against the tea mosquito bug Helopeltis theivora — with chitin hydrolysis of the insect exoskeleton cited as the mechanism of action.

Literature on P. fluorescens DR397, isolated from drought-prone soybean rhizosphere soil, reports shoot and root growth increases of 62–149% in Pisum sativum and Phaseolus vulgaris under drought stress compared to controls. Genomic analysis identified genes for compatible-solute synthesis, exopolysaccharide production, and indole-3-acetic acid synthesis, with expression of these genes upregulated specifically under drought plus root-exudate conditions.

An open-field tomato trial found that a biostimulant containing P. fluorescens and Bacillus amyloliquefaciens shifted native rhizosphere alpha and beta diversity, raising nitrogen-fixing microbe density. A separate Arabidopsis mechanistic study reports that the PSKR1 receptor suppresses salicylic-acid-mediated plant defenses during P. fluorescens colonization, providing insight into the host-immunity trade-offs governing plant-growth-promoting rhizobacterium interactions.