title: Receptor-mediated exopolysaccharide perception controls bacterial infection.
abstract: Surface polysaccharides are important for bacterial interactions with multicellular organisms, and some are virulence factors in pathogens. In the legume-rhizobium symbiosis, bacterial exopolysaccharides (EPS) are essential for the development of infected root nodules. We have identified a gene in Lotus japonicus, Epr3, encoding a receptor-like kinase that controls this infection. We show that epr3 mutants are defective in perception of purified EPS, and that EPR3 binds EPS directly and distinguishes compatible and incompatible EPS in bacterial competition studies. Expression of Epr3 in epidermal cells within the susceptible root zone shows that the protein is involved in bacterial entry, while rhizobial and plant mutant studies suggest that Epr3 regulates bacterial passage through the plant's epidermal cell layer. Finally, we show that Epr3 expression is inducible and dependent on host perception of bacterial nodulation (Nod) factors. Plant-bacterial compatibility and bacterial access to legume roots is thus regulated by a two-stage mechanism involving sequential receptor-mediated recognition of Nod factor and EPS signals.
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: Y
authors.initials: Y
authors.lastname: Kawaharada
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark [3] Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand.
authors.forename: S
authors.initials: S
authors.lastname: Kelly
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: M Wibroe
authors.initials: MW
authors.lastname: Nielsen
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Chemistry, University of Copenhagen, Frederiksberg 1871 C, Denmark.
authors.forename: C T
authors.initials: CT
authors.lastname: Hjuler
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Gysel
authors.affiliation: Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA.
authors.forename: A
authors.initials: A
authors.lastname: Muszyński
authors.affiliation: Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Carlson
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Chemistry, University of Copenhagen, Frederiksberg 1871 C, Denmark.
authors.forename: M B
authors.initials: MB
authors.lastname: Thygesen
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: N
authors.initials: N
authors.lastname: Sandal
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: M H
authors.initials: MH
authors.lastname: Asmussen
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Vinther
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: S U
authors.initials: SU
authors.lastname: Andersen
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Krusell
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Thirup
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Chemistry, University of Copenhagen, Frederiksberg 1871 C, Denmark.
authors.forename: K J
authors.initials: KJ
authors.lastname: Jensen
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand.
authors.forename: C W
authors.initials: CW
authors.lastname: Ronson
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Blaise
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Radutoiu
authors.affiliation: 1] Centre for Carbohydrate Recognition and Signalling. Aarhus University, Aarhus 8000 C, Denmark [2] Department of Molecular Biology and Genetics, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Stougaard
mesh_terms: D000595:Amino Acid Sequence; D002240:Carbohydrate Sequence; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism*; D000070116:Lotus / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D019441:Plant Epidermis / Q000378:metabolism / Q000382:microbiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D055170:Plant Root Nodulation; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012231:Rhizobium / Q000378:metabolism*; D053204:Root Nodules, Plant / Q000378:metabolism / Q000382:microbiology; D015398:Signal Transduction; D013045:Species Specificity; D013489:Suppression, Genetic / Q000235:genetics; D013559:Symbiosis
chemical_list: D008070:Lipopolysaccharides; D010940:Plant Proteins; D011956:Receptors, Cell Surface; D011494:Protein Kinases