title: Two Lotus japonicus symbiosis mutants impaired at distinct steps of arbuscule development.
abstract: Arbuscular mycorrhiza (AM) fungi form nutrient-acquiring symbioses with the majority of higher plants. Nutrient exchange occurs via arbuscules, highly branched hyphal structures that are formed within root cortical cells. With a view to identifying host genes involved in AM development, we isolated Lotus japonicus AM-defective mutants via a microscopic screen of an ethyl methanesulfonate-mutagenized population. A standardized mapping procedure was developed that facilitated positioning of the defective loci on the genetic map of L. japonicus, and, in five cases, allowed identification of mutants of known symbiotic genes. Two additional mutants representing independent loci did not form mature arbuscules during symbiosis with two divergent AM fungal species, but exhibited signs of premature arbuscule arrest or senescence. Marker gene expression patterns indicated that the two mutants are affected in distinct steps of arbuscule development. Both mutants formed wild-type-like root nodules upon inoculation with Mesorhizobium loti, indicating that the mutated loci are essential during AM but not during root nodule symbiosis.
authors.affiliation: Faculty of Biology, Genetics, University of Munich, Großhaderner Straße 2-4, 82152, Martinsried, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Groth
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK.
authors.forename: Sonja
authors.initials: S
authors.lastname: Kosuta
authors.affiliation: Faculty of Biology, Genetics, University of Munich, Großhaderner Straße 2-4, 82152, Martinsried, Germany.
authors.forename: Caroline
authors.initials: C
authors.lastname: Gutjahr
authors.affiliation: Faculty of Biology, Genetics, University of Munich, Großhaderner Straße 2-4, 82152, Martinsried, Germany.
authors.forename: Kristina
authors.initials: K
authors.lastname: Haage
authors.affiliation: Faculty of Biology, Genetics, University of Munich, Großhaderner Straße 2-4, 82152, Martinsried, Germany.
authors.forename: Simone Liesel
authors.initials: SL
authors.lastname: Hardel
authors.affiliation: Faculty of Biology, Genetics, University of Munich, Großhaderner Straße 2-4, 82152, Martinsried, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Schaub
authors.affiliation: Faculty of Biology, Genetics, University of Munich, Großhaderner Straße 2-4, 82152, Martinsried, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Brachmann
authors.affiliation: Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba, 292-0818, Japan.
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.affiliation: Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba, 292-0818, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.affiliation: John Innes Centre, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK.
authors.forename: Kim
authors.initials: K
authors.lastname: Findlay
authors.affiliation: John Innes Centre, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK.
authors.forename: Trevor L
authors.initials: TL
authors.lastname: Wang
authors.affiliation: Faculty of Biology, Genetics, University of Munich, Großhaderner Straße 2-4, 82152, Martinsried, Germany.|The Sainsbury Laboratory, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Parniske
mesh_terms: D002874:Chromosome Mapping; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D005658:Fungi / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure; D018506:Gene Expression Regulation, Plant; D056426:Genetic Loci; D025301:Hyphae; D000070116:Lotus / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology / Q000648:ultrastructure; D059128:Mesorhizobium / Q000502:physiology*; D009154:Mutation; D038821:Mycorrhizae / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000235:genetics / Q000382:microbiology / Q000648:ultrastructure; D053204:Root Nodules, Plant; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D010940:Plant Proteins; D005020:Ethyl Methanesulfonate