Plant-based infection models provide cost effective and biologically relevant systems for investigating bacterial pathogenesis and virulence in living hosts. The mung bean seedling model enables the study of bacterial biofilms on living surfaces by allowing attachment and biofilm development on plants, but its broader use has been limited by methodological complexity and variability in experimental outcomes. Here, we present a modified mung bean seedling biofilm infection model for assessing Pseudomonas aeruginosa virulence that improves both consistency and practicality. The assay incorporates a bleach-based seed sterilization protocol that effectively reduces surface associated contaminants while maintaining high seed germination percentages. Additional refinements, including dehulling germinated seedlings, a shortened bacterial inoculation period, and plate-based incubation of seedlings at 37°C, minimize variability in plant health outcomes while supporting development of gnotobiotic plants. Plant mortality, cotyledon emergence, and root branching were identified as rapid and quantitative measures of biofilm associated disease. Using this modified assay, reproducible differences in virulence were detected among P. aeruginosa strains, including reduced pathogenicity in a pqsR quorum sensing mutant. This simplified mung bean seedling model provides an accessible platform for studying biofilm associated virulence and screening genes involved in biofilm-mediated pathogenicity on a biotic surface.
Williamson et al. (Wed,) studied this question.