title: The receptor-like kinase KLAVIER mediates systemic regulation of nodulation and non-symbiotic shoot development in Lotus japonicus.
abstract: In legumes, the number of symbiotic root nodules is controlled by long-distance communication between the shoot and the root. Mutants defective in this feedback mechanism exhibit a hypernodulating phenotype. Here, we report the identification of a novel leucine-rich repeat receptor-like kinase (LRR-RLK), KLAVIER (KLV), which mediates the systemic negative regulation of nodulation in Lotus japonicus. In leaf, KLV is predominantly expressed in the vascular tissues, as with another LRR-RLK gene, HAR1, which also regulates nodule number. A double-mutant analysis indicated that KLV and HAR1 function in the same genetic pathway that governs the negative regulation of nodulation. LjCLE-RS1 and LjCLE-RS2 represent potential root-derived mobile signals for the HAR1-mediated systemic regulation of nodulation. Overexpression of LjCLE-RS1 or LjCLE-RS2 did not suppress the hypernodulation phenotype of the klv mutant, indicating that KLV is required and acts downstream of LjCLE-RS1 and LjCLE-RS2. In addition to the role of KLV in symbiosis, complementation tests and expression analyses indicated that KLV plays multiple roles in shoot development, including maintenance of shoot apical meristem, vascular continuity, shoot growth and promotion of flowering. Biochemical analyses using transient expression in Nicotiana benthamiana revealed that KLV has the ability to interact with HAR1 and with itself. Together, these results suggest that the potential KLV-HAR1 receptor complex regulates symbiotic nodule development and that KLV is also a key component in other signal transduction pathways that mediate non-symbiotic shoot development.
authors.affiliation: Division of Symbiotic Systems, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan.
authors.forename: Hikota
authors.initials: H
authors.lastname: Miyazawa
authors.forename: Erika
authors.initials: E
authors.lastname: Oka-Kira
authors.forename: Naoto
authors.initials: N
authors.lastname: Sato
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Guo-Jiang
authors.initials: GJ
authors.lastname: Wu
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.forename: Masaki
authors.initials: M
authors.lastname: Hayashi
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Betsuyaku
authors.forename: Mikio
authors.initials: M
authors.lastname: Nakazono
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Kyuya
authors.initials: K
authors.lastname: Harada
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Sawa
authors.forename: Hiroo
authors.initials: H
authors.lastname: Fukuda
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kawaguchi
mesh_terms: D000070116:Lotus / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D013559:Symbiosis / Q000235:genetics / Q000502:physiology
chemical_list: D010940:Plant Proteins