The plant compound rosmarinic acid induces a broad quorum sensing response in Pseudomonas aeruginosa PAO1

Environ Microbiol. 2018 Dec;20(12):4230-4244. doi: 10.1111/1462-2920.14301. Epub 2018 Sep 10.

Abstract

The interference of plant compounds with bacterial quorum sensing (QS) is a major mechanism through which plants and bacteria communicate. However, little is known about the modes of action and effects on signal integrity during this type of communication. We have recently shown that the plant compound rosmarinic acid (RA) specifically binds to the Pseudomonas aeruginosa RhlR QS receptor. To determine the effect of RA on expression patterns, we carried out global RNA-seq analysis. The results show that RA induces the expression of 128 genes, amongst which many virulence factor genes. RA triggers a broad QS response because 88% of the induced genes are known to be controlled by QS, and because RA stimulated genes were found to be involved in all four QS signalling systems within P. aeruginosa. This finding was confirmed through the analysis of transcriptional fusions transferred to wt and a rhlI/lasI double mutant. RA did not induce gene expression in the rhlI/lasI/rhlR triple mutant indicating that the effects observed are due to the RA-RhlR interaction. Furthermore, RA induced seven sRNAs that were all encoded in regions close to QS and/or RA induced genes. This work significantly enhances our understanding of plant bacteria interaction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Carrier Proteins / metabolism
  • Cinnamates / metabolism
  • Cinnamates / pharmacology*
  • Depsides / metabolism
  • Depsides / pharmacology*
  • Gene Expression Regulation, Bacterial / drug effects*
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / metabolism*
  • Quorum Sensing / drug effects*
  • Quorum Sensing / genetics
  • Virulence Factors / genetics
  • Virulence Factors / metabolism

Substances

  • Bacterial Proteins
  • Carrier Proteins
  • Cinnamates
  • Depsides
  • Virulence Factors
  • rosmarinic acid