title: ABERRANT PANICLE ORGANIZATION 2/RFL, the rice ortholog of Arabidopsis LEAFY, suppresses the transition from inflorescence meristem to floral meristem through interaction with APO1.
abstract: The temporal and spatial control of meristem identity is a key element in plant development. To better understand the molecular mechanisms that regulate inflorescence and flower architecture, we characterized the rice aberrant panicle organization 2 (apo2) mutant which exhibits small panicles with reduced number of primary branches due to the precocious formation of spikelet meristems. The apo2 mutants also display a shortened plastochron in the vegetative phase, late flowering, aberrant floral organ identities and loss of floral meristem determinacy. Map-based cloning revealed that APO2 is identical to previously reported RFL gene, the rice ortholog of the Arabidopsis LEAFY (LFY) gene. Further analysis indicated that APO2/RFL and APO1, the rice ortholog of Arabidopsis UNUSUAL FLORAL ORGANS, act cooperatively to control inflorescence and flower development. The present study revealed functional differences between APO2/RFL and LFY. In particular, APO2/RFL and LFY act oppositely on inflorescence development. Therefore, the genetic mechanisms for controlling inflorescence architecture have evolutionarily diverged between rice (monocots) and Arabidopsis (eudicots).
authors.affiliation: Graduate School of Agriculture and Life Sciences, University of Tokyo, Yayoi, Bunkyo, Tokyo 113-0032, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Ikeda-Kawakatsu
authors.forename: Masahiko
authors.initials: M
authors.lastname: Maekawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Izawa
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Itoh
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nagato
mesh_terms: D029681:Arabidopsis Proteins / Q000378:metabolism*; D003001:Cloning, Molecular; D035264:Flowers / Q000235:genetics / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D056626:Inflorescence; D018519:Meristem / Q000235:genetics* / Q000254:growth & development*; D009154:Mutation; D012275:Oryza / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C074747:LFY protein, Arabidopsis; D010940:Plant Proteins; D014157:Transcription Factors