title: Bradyrhizobium BclA Is a Peptide Transporter Required for Bacterial Differentiation in Symbiosis with Aeschynomene Legumes.
abstract: Nodules of legume plants are highly integrated symbiotic systems shaped by millions of years of evolution. They harbor nitrogen-fixing rhizobium bacteria called bacteroids. Several legume species produce peptides called nodule-specific cysteine-rich (NCR) peptides in the symbiotic nodule cells which house the bacteroids. NCR peptides are related to antimicrobial peptides of innate immunity. They induce the endosymbionts into a differentiated, enlarged, and polyploid state. The bacterial symbionts, on their side, evolved functions for the response to the NCR peptides. Here, we identified the bclA gene of Bradyrhizobium sp. strains ORS278 and ORS285, which is required for the formation of differentiated and functional bacteroids in the nodules of the NCR peptide-producing Aeschynomene legumes. The BclA ABC transporter promotes the import of NCR peptides and provides protection against the antimicrobial activity of these peptides. Moreover, BclA can complement the role of the related BacA transporter of Sinorhizobium meliloti, which has a similar symbiotic function in the interaction with Medicago legumes.
authors.affiliation: 1 Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Université Paris-Sud/CEA, Gif-sur-Yvette, France;|2 Research Unit Biodiversity & Valorization of Arid Areas Bioressources (BVBAA), Faculty of Sciences, Gabès, Tunisia;
authors.forename: Ibtissem
authors.initials: I
authors.lastname: Guefrachi
authors.affiliation: 1 Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Université Paris-Sud/CEA, Gif-sur-Yvette, France;
authors.forename: Olivier
authors.initials: O
authors.lastname: Pierre
authors.affiliation: 1 Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Université Paris-Sud/CEA, Gif-sur-Yvette, France;
authors.forename: Tatiana
authors.initials: T
authors.lastname: Timchenko
authors.affiliation: 1 Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Université Paris-Sud/CEA, Gif-sur-Yvette, France;
authors.forename: Benoît
authors.initials: B
authors.lastname: Alunni
authors.affiliation: 1 Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Université Paris-Sud/CEA, Gif-sur-Yvette, France;
authors.forename: Quentin
authors.initials: Q
authors.lastname: Barrière
authors.affiliation: 3 Laboratoire des Symbioses Tropicales et Méditerranéennes, Institut pour la Recherche et le Développement, UMR IRD/SupAgro/INRA/UM2/CIRAD, Montpellier, France;
authors.forename: Pierre
authors.initials: P
authors.lastname: Czernic
authors.affiliation: 1 Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Université Paris-Sud/CEA, Gif-sur-Yvette, France;
authors.forename: José-Antonio
authors.initials: JA
authors.lastname: Villaécija-Aguilar
authors.affiliation: 1 Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Université Paris-Sud/CEA, Gif-sur-Yvette, France;
authors.forename: Camille
authors.initials: C
authors.lastname: Verly
authors.affiliation: 1 Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Université Paris-Sud/CEA, Gif-sur-Yvette, France;
authors.forename: Mickaël
authors.initials: M
authors.lastname: Bourge
authors.affiliation: 3 Laboratoire des Symbioses Tropicales et Méditerranéennes, Institut pour la Recherche et le Développement, UMR IRD/SupAgro/INRA/UM2/CIRAD, Montpellier, France;
authors.forename: Joël
authors.initials: J
authors.lastname: Fardoux
authors.affiliation: 2 Research Unit Biodiversity & Valorization of Arid Areas Bioressources (BVBAA), Faculty of Sciences, Gabès, Tunisia;
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mars
authors.affiliation: 1 Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Université Paris-Sud/CEA, Gif-sur-Yvette, France;|4 Institute of Biochemistry, Hungarian Academy of Sciences, Biological Research Centre, Szeged, Hungary.
authors.forename: Eva
authors.initials: E
authors.lastname: Kondorosi
authors.affiliation: 3 Laboratoire des Symbioses Tropicales et Méditerranéennes, Institut pour la Recherche et le Développement, UMR IRD/SupAgro/INRA/UM2/CIRAD, Montpellier, France;
authors.forename: Eric
authors.initials: E
authors.lastname: Giraud
authors.affiliation: 1 Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Université Paris-Sud/CEA, Gif-sur-Yvette, France;
authors.forename: Peter
authors.initials: P
authors.lastname: Mergaert
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D020369:Bradyrhizobium / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D007887:Fabaceae / Q000378:metabolism / Q000382:microbiology; D005434:Flow Cytometry; D005816:Genetic Complementation Test; D054884:Host-Pathogen Interactions; D029902:Medicago / Q000378:metabolism / Q000382:microbiology; D026901:Membrane Transport Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009154:Mutation; D010455:Peptides / Q000378:metabolism; D010802:Phylogeny; D011123:Polyploidy; D053204:Root Nodules, Plant / Q000378:metabolism / Q000382:microbiology; D016962:Sinorhizobium meliloti / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D010455:Peptides; C043912:peptide permease