title: Genome-wide RNA sequencing analysis of quorum sensing-controlled regulons in the plant-associated Burkholderia glumae PG1 strain.
abstract: Burkholderia glumae PG1 is a soil-associated motile plant-pathogenic bacterium possessing a cell density-dependent regulation system called quorum sensing (QS). Its genome contains three genes, here designated bgaI1 to bgaI3, encoding distinct autoinducer-1 (AI-1) synthases, which are capable of synthesizing QS signaling molecules. Here, we report on the construction of B. glumae PG1 ΔbgaI1, ΔbgaI2, and ΔbgaI3 mutants, their phenotypic characterization, and genome-wide transcriptome analysis using RNA sequencing (RNA-seq) technology. Knockout of each of these bgaI genes resulted in strongly decreased motility, reduced extracellular lipase activity, a reduced ability to cause plant tissue maceration, and decreased pathogenicity. RNA-seq analysis of all three B. glumae PG1 AI-1 synthase mutants performed in the transition from exponential to stationary growth phase revealed differential expression of a significant number of predicted genes. In comparison with the levels of gene expression by wild-type strain B. glumae PG1, 481 genes were differentially expressed in the ΔbgaI1 mutant, 213 were differentially expressed in the ΔbgaI2 mutant, and 367 were differentially expressed in the ΔbgaI3 mutant. Interestingly, only a minor set of 78 genes was coregulated in all three mutants. The majority of the QS-regulated genes were linked to metabolic activities, and the most pronounced regulation was observed for genes involved in rhamnolipid and Flp pilus biosynthesis and the type VI secretion system and genes linked to a clustered regularly interspaced short palindromic repeat (CRISPR)-cas gene cluster.
authors.affiliation: Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany.
authors.forename: Rong
authors.initials: R
authors.lastname: Gao
authors.affiliation: Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Krysciak
authors.affiliation: Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Petersen
authors.affiliation: Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Utpatel
authors.affiliation: Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Knapp
authors.affiliation: Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany.
authors.forename: Christel
authors.initials: C
authors.lastname: Schmeisser
authors.affiliation: Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg August University Göttingen, Göttingen, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Daniel
authors.affiliation: Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg August University Göttingen, Göttingen, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Voget
authors.affiliation: Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Karl-Erich
authors.initials: KE
authors.lastname: Jaeger
authors.affiliation: Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany wolfgang.streit@uni-hamburg.de.
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Streit
mesh_terms: D019117:Burkholderia / Q000235:genetics*; D020869:Gene Expression Profiling; D053038:Quorum Sensing; D018085:Regulon; D017423:Sequence Analysis, RNA; D017384:Sequence Deletion; D059467:Transcriptome