title: ABERRANT PANICLE ORGANIZATION 1 temporally regulates meristem identity in rice.
abstract: We report a recessive mutation of rice, aberrant panicle organization 1 (apo1), which severely affects inflorescence architecture, floral organ identity, and leaf production rate. In the wild-type inflorescence, the main-axis meristem aborts after forming 10-12 primary branch primordia. However, in apo1, the main-axis meristem was converted to a spikelet meristem after producing a small number of branch primordia. In addition, the branch meristems in apo1 became spikelet meristems earlier than in wild type. Therefore, in the inflorescence, the apo1 mutation caused the precocious conversion of the meristem identity. In the apo1 flower, lodicules were increased at the expense of stamens, and carpels were formed indeterminately by the loss of meristem determinacy. Vegetative development is also affected in the apo1. Leaves were formed rapidly throughout the vegetative phase, indicating that APO1 is also involved in temporal regulation of leaf production. These phenotypes suggest that the APO1 plays an important role in the temporal regulation of both vegetative and reproductive development.
authors.affiliation: Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Ikeda
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Nagasawa
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nagato
mesh_terms: D002454:Cell Differentiation / Q000502:physiology*; D035264:Flowers / Q000235:genetics / Q000254:growth & development*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D017403:In Situ Hybridization; D018519:Meristem / Q000502:physiology* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D009154:Mutation / Q000235:genetics; D012275:Oryza / Q000235:genetics* / Q000254:growth & development*; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development