title: A plant receptor-like kinase required for both bacterial and fungal symbiosis.
abstract: Most higher plant species can enter a root symbiosis with arbuscular mycorrhizal fungi, in which plant carbon is traded for fungal phosphate. This is an ancient symbiosis, which has been detected in fossils of early land plants. In contrast, the nitrogen-fixing root nodule symbioses of plants with bacteria evolved more recently, and are phylogenetically restricted to the rosid I clade of plants. Both symbioses rely on partially overlapping genetic programmes. We have identified the molecular basis for this convergence by cloning orthologous SYMRK ('symbiosis receptor-like kinase') genes from Lotus and pea, which are required for both fungal and bacterial recognition. SYMRK is predicted to have a signal peptide, an extracellular domain comprising leucine-rich repeats, a transmembrane and an intracellular protein kinase domain. Lotus SYMRK is required for a symbiotic signal transduction pathway leading from the perception of microbial signal molecules to rapid symbiosis-related gene activation. The perception of symbiotic fungi and bacteria is mediated by at least one common signalling component, which could have been recruited during the evolution of root nodule symbioses from the already existing arbuscular mycorrhiza symbiosis.
authors.affiliation: The Sainsbury Laboratory, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK.
authors.forename: Silke
authors.initials: S
authors.lastname: Stracke
authors.forename: Catherine
authors.initials: C
authors.lastname: Kistner
authors.forename: Satoko
authors.initials: S
authors.lastname: Yoshida
authors.forename: Lonneke
authors.initials: L
authors.lastname: Mulder
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.forename: Takakazu
authors.initials: T
authors.lastname: Kaneko
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Niels
authors.initials: N
authors.lastname: Sandal
authors.forename: Jens
authors.initials: J
authors.lastname: Stougaard
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Szczyglowski
authors.forename: Martin
authors.initials: M
authors.lastname: Parniske
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D005658:Fungi / Q000378:metabolism / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D000070116:Lotus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009586:Nitrogen Fixation; D018532:Pisum sativum / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D021382:Protein Sorting Signals; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012231:Rhizobium / Q000378:metabolism / Q000502:physiology*; D013559:Symbiosis / Q000235:genetics; D015533:Transcriptional Activation
chemical_list: D021382:Protein Sorting Signals; D018749:RNA, Plant; D011494:Protein Kinases