Down Regulation of Virulence Factors of Pseudomonas aeruginosa by Salicylic Acid Attenuates Its Virulence on Arabidopsis thaliana and Caenorhabditis elegans

摘要: Salicylic acid (SA) is a phenolic metabolite produced by plants and known to play an important role in several physiological processes, such as the induction of plant defense responses against pathogen attack. Here, using Arabidopsis thaliana-Pseudomonas aeruginosa pathosystem, we provide evidence that SA acts directly on pathogen, down regulating fitness virulence factor production bacteria. Pseudomonas PA14 showed reduced attachment biofilm formation roots mutants lox2 cpr5-2, which produce elevated amounts SA, well wild-type primed with exogenous treatment enhance endogenous concentration. at concentration did not inhibit growth was sufficient significantly affect ability bacteria attach form communities abiotic surfaces. Furthermore, regulated three factors PA14: pyocyanin, protease, elastase. Interestingly, P. more pyocyanin when infiltrated into leaves transgenic line NahG, accumulates less than plants. This finding suggests plays synthesis secretion vivo. To further test if affects aeruginosa, used Caenorhabiditis elegans-P. infection model. The addition lawns diminished bacterium's kill worms, without affecting accumulation inside nematodes' guts, suggesting negatively influence aeruginosa. We employed microarray technology identify target genes. These analyses affected expression 331 It selectively repressed transcription exoproteins other factors, while it had no effect housekeeping Our results indicate its signal molecule responses, works anti-infective compound physiology ultimately attenuating virulence.