title: PLASTOCHRON2 regulates leaf initiation and maturation in rice.
abstract: In higher plants, leaves initiate in constant spatial and temporal patterns. Although the pattern of leaf initiation is a key element of plant shoot architecture, little is known about how the time interval between initiation events, termed plastochron, is regulated. Here, we present a detailed analysis of plastochron2 (pla2), a rice (Oryza sativa) mutant that exhibits shortened plastochron and precocious maturation of leaves during the vegetative phase and ectopic shoot formation during the reproductive phase. The corresponding PLA2 gene is revealed to be an orthologue of terminal ear1, a maize (Zea mays) gene that encodes a MEI2-like RNA binding protein. PLA2 is expressed predominantly in young leaf primordia. We show that PLA2 normally acts to retard the rate of leaf maturation but does so independently of PLA1, which encodes a member of the P450 family. Based on these analyses, we propose a model in which plastochron is determined by signals from immature leaves that act non-cell-autonomously in the shoot apical meristem to inhibit the initiation of new leaves.
authors.affiliation: Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan.
authors.forename: Taiji
authors.initials: T
authors.lastname: Kawakatsu
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Itoh
authors.forename: Kazumaru
authors.initials: K
authors.lastname: Miyoshi
authors.forename: Nori
authors.initials: N
authors.lastname: Kurata
authors.forename: Nena
authors.initials: N
authors.lastname: Alvarez
authors.forename: Bruce
authors.initials: B
authors.lastname: Veit
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nagato
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D017343:Genes, Plant; D018519:Meristem / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000033:anatomy & histology / Q000254:growth & development* / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D018515:Plant Leaves / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018547:Plant Stems / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D012098:Reproduction; D017386:Sequence Homology, Amino Acid
chemical_list: D010940:Plant Proteins; D016601:RNA-Binding Proteins