title: Differential regulation of the Epr3 receptor coordinates membrane-restricted rhizobial colonization of root nodule primordia.
abstract: In Lotus japonicus, a LysM receptor kinase, EPR3, distinguishes compatible and incompatible rhizobial exopolysaccharides at the epidermis. However, the role of this recognition system in bacterial colonization of the root interior is unknown. Here we show that EPR3 advances the intracellular infection mechanism that mediates infection thread invasion of the root cortex and nodule primordia. At the cellular level, Epr3 expression delineates progression of infection threads into nodule primordia and cortical infection thread formation is impaired in epr3 mutants. Genetic dissection of this developmental coordination showed that Epr3 is integrated into the symbiosis signal transduction pathways. Further analysis showed differential expression of Epr3 in the epidermis and cortical primordia and identified key transcription factors controlling this tissue specificity. These results suggest that exopolysaccharide recognition is reiterated during the progressing infection and that EPR3 perception of compatible exopolysaccharide promotes an intracellular cortical infection mechanism maintaining bacteria enclosed in plant membranes.
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kawaharada
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark.
authors.forename: Mette W
authors.initials: MW
authors.lastname: Nielsen
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark.
authors.forename: Simon
authors.initials: S
authors.lastname: Kelly
authors.affiliation: The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK.
authors.forename: Euan K
authors.initials: EK
authors.lastname: James
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark.
authors.forename: Kasper R
authors.initials: KR
authors.lastname: Andersen
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark.
authors.forename: Sheena R
authors.initials: SR
authors.lastname: Rasmussen
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark.
authors.forename: Winnie
authors.initials: W
authors.lastname: Füchtbauer
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark.
authors.forename: Lene H
authors.initials: LH
authors.lastname: Madsen
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark.
authors.forename: Anne B
authors.initials: AB
authors.lastname: Heckmann
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark.
authors.forename: Simona
authors.initials: S
authors.lastname: Radutoiu
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Stougaard
mesh_terms: D002462:Cell Membrane / Q000378:metabolism*; D015169:Colony Count, Microbial; D018506:Gene Expression Regulation, Plant; D000070116:Lotus / Q000235:genetics* / Q000382:microbiology*; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011134:Polysaccharides / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012231:Rhizobium / Q000502:physiology*; D053204:Root Nodules, Plant / Q000235:genetics* / Q000382:microbiology*; D013559:Symbiosis / Q000235:genetics; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D011134:Polysaccharides; D012333:RNA, Messenger; D014157:Transcription Factors