title: Intraradical colonization by arbuscular mycorrhizal fungi triggers induction of a lipochitooligosaccharide receptor.
abstract: Functional divergence of paralogs following gene duplication is one of the mechanisms leading to evolution of novel pathways and traits. Here we show that divergence of Lys11 and Nfr5 LysM receptor kinase paralogs of Lotus japonicus has affected their specificity for lipochitooligosaccharides (LCOs) decorations, while the innate capacity to recognize and induce a downstream signalling after perception of rhizobial LCOs (Nod factors) was maintained. Regardless of this conserved ability, Lys11 was found neither expressed, nor essential during nitrogen-fixing symbiosis, providing an explanation for the determinant role of Nfr5 gene during Lotus-rhizobia interaction. Lys11 was expressed in root cortex cells associated with intraradical colonizing arbuscular mycorrhizal fungi. Detailed analyses of lys11 single and nfr1nfr5lys11 triple mutants revealed a functional arbuscular mycorrhizal symbiosis, indicating that Lys11 alone, or its possible shared function with the Nod factor receptors is not essential for the presymbiotic phases of AM symbiosis. Hence, both subfunctionalization and specialization appear to have shaped the function of these paralogs where Lys11 acts as an AM-inducible gene, possibly to fine-tune later stages of this interaction.
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Denmark.
authors.forename: S R
authors.initials: SR
authors.lastname: Rasmussen
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Denmark.
authors.forename: W
authors.initials: W
authors.lastname: Füchtbauer
authors.affiliation: Department of Life Science and Systems Biology, University of Torino, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Novero
authors.affiliation: Department of Life Science and Systems Biology, University of Torino, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Volpe
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Denmark.
authors.forename: N
authors.initials: N
authors.lastname: Malkov
authors.affiliation: Department of Life Science and Systems Biology, University of Torino, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Genre
authors.affiliation: Department of Life Science and Systems Biology, University of Torino, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Bonfante
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Stougaard
authors.affiliation: Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Radutoiu
mesh_terms: D000595:Amino Acid Sequence; D002240:Carbohydrate Sequence; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant; D054884:Host-Pathogen Interactions; D008070:Lipopolysaccharides / Q000378:metabolism*; D000070116:Lotus / Q000235:genetics / Q000382:microbiology*; D009154:Mutation; D038821:Mycorrhizae / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000382:microbiology*; D030821:Plants, Genetically Modified; D012231:Rhizobium / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D013559:Symbiosis
chemical_list: D008070:Lipopolysaccharides; D010940:Plant Proteins; C023023:lipid-linked oligosaccharides