title: DWARF10, an RMS1/MAX4/DAD1 ortholog, controls lateral bud outgrowth in rice.
abstract: Plant architecture is mostly determined by shoot branching patterns. Apical dominance is a well-known control mechanism in the development of branching patterns, but little is known regarding its role in monocots such as rice. Here, we show that the concept of apical dominance can be applied to tiller bud outgrowth of rice. In dwarf10 (d10), an enhanced branching mutant of rice, apical dominance can be observed, but the inhibitory effects of the apical meristem was reduced. D10 is a rice ortholog of MAX4/RMS1/DAD1 that encodes a carotenoid cleavage dioxygenase 8 and is supposed to be involved in the synthesis of an unidentified inhibitor of shoot branching. D10 expression predominantly occurs in vascular cells in most organs. Real-time polymerase chain reaction analysis revealed that accumulation of D10 mRNA is induced by exogenous auxin. Moreover, D10 expression is upregulated in six branching mutants, d3, d10, d14, d17, d27 and high tillering dwarf (htd1). No such effects were found for D3 or HTD1, the MAX2 and MAX3 orthologs, respectively, of rice. These findings imply that D10 transcription might be a critical step in the regulation of the branching inhibitor pathway. In addition, we present observations that suggest that FINE CULM1 (FC1), a rice ortholog of teosinte branched 1 (tb1), possibly works independently of the branching inhibitor pathway.
authors.affiliation: Graduate School of Agriculture and Life Sciences, University of Tokyo, Yayoi, Bunkyo, Tokyo 113-0032, Japan.
authors.forename: Tomotsugu
authors.initials: T
authors.lastname: Arite
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Iwata
authors.forename: Kenji
authors.initials: K
authors.lastname: Ohshima
authors.forename: Masahiko
authors.initials: M
authors.lastname: Maekawa
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nakajima
authors.forename: Mikiko
authors.initials: M
authors.lastname: Kojima
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sakakibara
authors.forename: Junko
authors.initials: J
authors.lastname: Kyozuka
mesh_terms: D003001:Cloning, Molecular; D049308:Dioxygenases / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D025461:Feedback, Physiological; D007210:Indoleacetic Acids / Q000494:pharmacology; D009154:Mutation; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D010940:Plant Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D016133:Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins; D049308:Dioxygenases