Project description:Pseudomonas species are ubiquitous in plant-associated environments and produce an array of volatiles, enzymes and antimicrobials. The biosynthesis of many metabolites is regulated by the GacS/GacA two-component regulatory system. Transcriptome analysis of Pseudomonas fluorescens SBW25 revealed that 702 genes were differentially regulated (fold change>4, P<0.0001) in a gacS::Tn5 mutant, with 300 and 402 genes up- and down-regulated, respectively. Genes that were significantly down-regulated are involved in viscosin biosynthesis (viscABC), protease production (aprA), motility, biofilm formation, and secretory systems. Genes that were significantly up-regulated are involved in siderophore biosynthesis and oxidative stress. In contrast to previous studies with gac-mutants of other Pseudomonas species/strains, the gacS mutant of SBW25 inhibited growth of oomycete, fungal and bacterial pathogens significantly more than parental strain SBW25. A potential candidate for this enhanced antimicrobial activity was a large nonribosomal peptide synthetase (NRPS) gene cluster predicted to encode for an 8-amino-acid ornicorrugatin-like peptide. Site-directed mutagenesis of an NRPS gene in this cluster, however, did not lead to a reduction in the antimicrobial activity of the gacS mutant. Collectively these results indicate that a mutation in the GacS/GacA regulatory system causes major transcriptional changes in P. fluorescens SBW25 and significantly enhances its antimicrobial activities by yet unknown mechanisms. This expression study used total RNA recovered from four separate wild-type cultures of Pseudomonas fluorescens SBW25 and four separate cultures of the gacS mutant. Expression design was based on the updated genome sequence of Pseudomonas fluorescens SBW25, NC_012660.1 and associated plasmid pQBR0476 with nineteen 60-mer probe per gene. Each probe is replicated 3 times. The design includes random GC and other control probes.
Project description:This SuperSeries is composed of the following subset Series: GSE29319: Iron-starvation effect on transcriptome of Pseudomonas fluorescens Pf-5: iron(II) chloride GSE29320: Iron-starvation effect on transcriptome of Pseudomonas fluorescens Pf-5: iron(III) chloride Refer to individual Series
Project description:This SuperSeries is composed of the following subset Series: GSE33907: Tannic acid (20 µg/ mL) treatment effect on transcriptome of Pseudomonas fluorescens Pf-5 GSE33908: Tannic acid (160 µg/ mL) treatment effect on transcriptome of Pseudomonas fluorescens Pf-5 Refer to individual Series
Project description:ra13-03_pyo - effect of pseudomonas fluorescens pyoverdine on a.thaliana defence responses and iron homeostasis - Analyse de l’effet d’un traitement par la pyoverdine sur les gènes liés à l’homéostasie du fer et à l’induction des réactions de défense. - Arabidopsis thaliana plants cultivated in hydroponic conditions were treated for 3 days by pyoverdin, a bacteriosiderophore from Pseudomonas fluorescens C7R12 in a medium supplemented or deprived of iron.
Project description:Whole genome gene expression study comparing Pseudomonas fluorescens Pf0-1 (Wt) relative to a delta-pst mutant (deletion of the pstSCAB operon) that consitutively expresses the Pho regulon Mutants used in this study are further described in Monds, R.D. Newell, P.D., Gross, R.H., O'Toole, G.A. (2007) Phosphate-dependent modulation of c-di-GMP levels regulates Pseudomonas fluorescens Pf0-1 biofilm formation by controlling secretion of the adhesin LapA. Mol. Microbiol. 63(3): 656-679 A four chip study using total RNA recovered from two independent wild-type cultures of wild type strain Pseudomonas fluorescens Pf0-1 and two independent cultures of Pseudomonas fluorescens Pf0-1 delta pst mutant (deletion of the pstSCAB operon). Each chip measures the expression level of 5733 open reading frames (ORFs) genes from Pseudomonas fluorescens Pf0-1 (Refseq: NC_007492) with twenty 60-mer postive match (PM) probes per gene, with three-fold technical redundancy.
Project description:The goal of this study was to evaluate the molecular mechanisms by which Brachypodium distachyon grown with and without Pseudomonas fluorescens (P. fluorescens) strain SBW25 respond to Fe deprivation. Fe deprivation induced Brachypodium secretion of phytosiderophores and reduced biomass production while inoculation with P. fluorescens resulted in alterations of extracellular metabolite abundances. Results provide insight into the role of iron in interactions between a host plant and root associated bacteria.
Project description:Transcriptomic profiling of Pseudomonas fluorescens Pf-5 comparing culture treated with 160 µg/mL tannic acid against non-treated culture grown in Mueller-Hinton media
Project description:Transcriptomic profiling of Pseudomonas fluorescens Pf-5 comparing culture treated with 20 µg/mL tannic acid against non-treated culture grown in Mueller-Hinton media
