Characterization of the SPI‐1 and Rsp type three secretion systems in Pseudomonas fluorescens F113. Issue 3 (25th February 2013)

• Record Type: Journal Article
• Authors: Barret, Matthieu; Egan, Frank; Moynihan, Jennifer; Morrissey, John P.; Lesouhaitier, Olivier; O'Gara, Fergal
• Is Part Of: Environmental microbiology reports. Volume 5:Issue 3(2013:Jun.)
• Page Start: 377
• Page End: 386
• Publication Date: 2013-02-25
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; Electronic journals; 579.17
• DOI: 10.1111/1758-2229.12039
• Languages: English
• ISSNs: 1758-2229

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p> <italic>Pseudomonas fluorescens</italic> F113 is a plant growth‐promoting rhizobacterium (PGPR) isolated from the sugar beet rhizosphere. The recent annotation of the F113 genome sequence has revealed that this strain encodes a wide array of secretion systems, including two complete type three secretion systems (T3SSs) belonging to the Hrp1 and SPI‐1 families. While Hrp1 T3SSs are frequently encoded in other <italic>P. fluorescens</italic> strains, the presence of a SPI‐1 T3SS in a plant‐beneficial bacterial strain was unexpected. In this work, the genetic organization and expression of these two T3SS loci have been analysed by a combination of transcriptional reporter fusions and transcriptome analyses. Overexpression of two transcriptional activators has shown a number of genes encoding putative T3 effectors. In addition, the influence of these two T3SSs during the interaction of <italic>P. fluorescens</italic> F113 with some bacterial predators was also assessed. Our data revealed that the transcriptional activator <italic>hilA</italic> is induced by amoeba and that the SPI‐1 T3SS could potentially be involved in resistance to amoeboid grazing.</p> </abstract>