title: The Absence of the N-acyl-homoserine-lactone Autoinducer Synthase GenestraIandngrIIncreases the Copy Number of the Symbiotic Plasmid inSinorhizobium frediiNGR234.
abstract: Plant-released flavonoids induce the transcription of symbiotic genes in rhizobia and one of the first bacterial responses is the synthesis of so called Nod factors. They are responsible for the initial root hair curling during onset of root nodule development. This signal exchange is believed to be essential for initiating the plant symbiosis with rhizobia affiliated with theAlphaproteobacteria. Here, we provide evidence that in the broad host range strainSinorhizobium frediiNGR234 the complete lack of quorum sensing molecules results in an elevated copy number of its symbiotic plasmid (pNGR234a). This in turn triggers the expression of symbiotic genes and the production of Nod factors in the absence of plant signals. Therefore, increasing the copy number of specific plasmids could be a widespread mechanism of specialized bacterial populations to bridge gaps in signaling cascades.
authors.affiliation: Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
authors.forename: Jessica
authors.initials: J
authors.lastname: Grote
authors.affiliation: Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Krysciak
authors.affiliation: Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Petersen
authors.affiliation: Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Güllert
authors.affiliation: Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
authors.forename: Christel
authors.initials: C
authors.lastname: Schmeisser
authors.affiliation: Core Unit Systems Medicine, University of Würzburg Würzburg, Germany.
authors.forename: Konrad U
authors.initials: KU
authors.lastname: Förstner
authors.affiliation: Plant Genetics Research Unit, Agricultural Research Service, United States Department of Agriculture, University of Missouri Columbia, MO, USA.
authors.forename: Hari B
authors.initials: HB
authors.lastname: Krishnan
authors.affiliation: Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance Johann Wolfgang Goethe-University Frankfurt, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Schwalbe
authors.affiliation: Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance Johann Wolfgang Goethe-University Frankfurt, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Kubatova
authors.affiliation: Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Streit
keywords: RNA sequencing (RNA-Seq); Sinorhizobium fredii; plant symbioses; plasmid copy number; quorum sensing (QS)