title: The Clavata2 genes of pea and Lotus japonicus affect autoregulation of nodulation.
abstract: The number of root nodules developing on legume roots after rhizobial infection is controlled by the plant shoot through autoregulation and mutational inactivation of this mechanism leads to hypernodulation. We have characterised the Pisum sativum (pea) Sym28 locus involved in autoregulation and shown that it encodes a protein similar to the Arabidopsis CLAVATA2 (CLV2) protein. Inactivation of the PsClv2 gene in four independent sym28 mutant alleles, carrying premature stop codons, results in hypernodulation of the root and changes to the shoot architecture. In the reproductive phase sym28 shoots develops additional flowers, the stem fasciates, and the normal phyllotaxis is perturbed. Mutational substitution of an amino acid in one leucine rich repeat of the corresponding Lotus japonicus LjCLV2 protein results in increased nodulation. Similarly, down-regulation of the Lotus Clv2 gene by RNAi mediated reduction of the transcript level also resulted in increased nodulation. Gene expression analysis of LjClv2 and Lotus hypernodulation aberrant root formation Har1 (previously shown to regulate nodule numbers) indicated they have overlapping organ expression patterns. However, we were unable to demonstrate a direct protein-protein interaction between LjCLV2 and LjHAR1 proteins in contrast to the situation between equivalent proteins in Arabidopsis. LjHAR1 was localised to the plasma membrane using a YFP fusion whereas LjCLV2-YFP localised to the endoplasmic reticulum when transiently expressed in Nicotiana benthamiana leaves. This finding is the most likely explanation for the lack of interaction between these two proteins.
authors.affiliation: Centre for Carbohydrate Recognition and Signalling, Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10, DK-8000 Aarhus C, Denmark.
authors.forename: Lene
authors.initials: L
authors.lastname: Krusell
authors.forename: Naoto
authors.initials: N
authors.lastname: Sato
authors.forename: Izumi
authors.initials: I
authors.lastname: Fukuhara
authors.forename: Bjørn E V
authors.initials: BE
authors.lastname: Koch
authors.forename: Christina
authors.initials: C
authors.lastname: Grossmann
authors.forename: Satoru
authors.initials: S
authors.lastname: Okamoto
authors.forename: Erika
authors.initials: E
authors.lastname: Oka-Kira
authors.forename: Yoko
authors.initials: Y
authors.lastname: Otsubo
authors.forename: Grégoire
authors.initials: G
authors.lastname: Aubert
authors.forename: Tomomi
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Gerard
authors.initials: G
authors.lastname: Duc
authors.forename: Martin
authors.initials: M
authors.lastname: Parniske
authors.forename: Trevor L
authors.initials: TL
authors.lastname: Wang
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kawaguchi
authors.forename: Jens
authors.initials: J
authors.lastname: Stougaard
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D018744:DNA, Plant / Q000235:genetics; D017343:Genes, Plant; D006706:Homeostasis / Q000235:genetics / Q000502:physiology; D000070116:Lotus / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D008954:Models, Biological; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D018532:Pisum sativum / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology; D055170:Plant Root Nodulation / Q000235:genetics* / Q000502:physiology*; D030821:Plants, Genetically Modified; D034622:RNA Interference; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014026:Nicotiana / Q000235:genetics / Q000502:physiology
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins