Genome-wide analysis of the FleQ direct regulon in Pseudomonas fluorescens F113 and Pseudomonas putida KT2440

Sci Rep. 2018 Sep 3;8(1):13145. doi: 10.1038/s41598-018-31371-z.


Bacterial motility plays a crucial role in competitiveness and colonization in the rhizosphere. In this work, Chromatin ImmunoPrecipitation Sequencing (ChIP-seq) analysis has been used to identify genes putatively regulated by the transcriptional regulatory protein FleQ in Pseudomonas fluorescens F113 and Pseudomonas putida KT2440. This protein was previously identified as a master regulator of flagella and biofilm formation in both strains. This work has demonstrated that FleQ from both bacteria are conserved and functionally equivalent for motility regulation. Furthermore, the ChIP-seq analysis has shown that FleQ is a global regulator with the identification of 121 and 103 FleQ putative binding sites in P. fluorescens F113 and P. putida KT2440 respectively. Putative genes regulated by FleQ included, as expected, flagellar and motility-related genes and others involved in adhesion and exopolysaccharide production. Surprisingly, the ChIP-seq analysis also identified iron homeostasis-related genes for which positive regulation was shown by RT-qPCR. The results also showed that FleQ from P. fluorescens F113 shares an important part of its direct regulon with AmrZ, a global regulator also implicated in environmental adaption. Although AmrZ also regulates motility and iron uptake, the overlap occurred mostly with the iron-related genes, since both regulators control a different set of motility-related genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Binding Sites
  • Biofilms / growth & development
  • Flagella / genetics
  • Flagella / metabolism
  • Gene Expression Regulation, Bacterial*
  • Gene Ontology
  • Genome, Bacterial*
  • Iron / metabolism
  • Iron-Regulatory Proteins / genetics
  • Iron-Regulatory Proteins / metabolism
  • Molecular Sequence Annotation
  • Movement / physiology
  • Protein Binding
  • Pseudomonas fluorescens / genetics*
  • Pseudomonas fluorescens / metabolism
  • Pseudomonas putida / genetics*
  • Pseudomonas putida / metabolism
  • Regulon*
  • Trans-Activators / genetics*
  • Trans-Activators / metabolism


  • Bacterial Proteins
  • Iron-Regulatory Proteins
  • Trans-Activators
  • Iron