Genetic insights into biofilm enhancement: The impact of yicC gene disruption in Pseudomonas plecoglossicida NAN2

Biofilm formation plays a pivotal role in mediating plant-microbial interactions. However, despite its significance, the molecular mechanisms underlying biofilm formation by Pseudomonas plecoglossicida remain largely unexplored. Thus, this study aimed to identify genetic determinants involved in biofilm regulation by constructing a transposon mutant library of P. plecoglossicida NAN2. From the 2000 mutants screened, one mutant (M770) exhibited significantly superior biofilm production and distinct colony morphology and pellicle formation compared with the wild-type strain. Arbitrary PCR analysis revealed that the disrupted gene in M770 encoded a YicC family protein. Interestingly, despite the enhanced biofilm formation, root colonization assays indicated that the mutation in the yicC did not impair the ability of M770 to colonize plant roots. To the best of our knowledge, this is the first report on a transposon mutant with enhanced biofilm formation linked to a mutation in the yicC gene in P. plecoglossicida NAN2. These findings offer new insights into the regulatory role of the yicC in biofilm formation, providing potential targets for modulating biofilm dynamics in plant-microbe systems.