title: DWARF50 (D50), a rice (Oryza sativa L.) gene encoding inositol polyphosphate 5-phosphatase, is required for proper development of intercalary meristem.
abstract: Rice internodes are vital for supporting high-yield panicles, which are controlled by various factors such as cell division, cell elongation and cell wall biosynthesis. Therefore, formation and regulation of the internode cell-producing intercalary meristem (IM) are important for determining the shape of internodes. To understand the regulation of internode development, we analysed a rice dwarf mutant, dwarf 50 (d50). Previously, we reported that parenchyma cells in the elongated internodes of d50 ectopically deposit cell wall phenolics. In this study, we revealed that D50 encodes putative inositol polyphosphate 5-phosphatase (5PTase), which may be involved in phosphoinositide signalling required for many essential cellular functions, such as cytoskeleton organization, endocytosis and vesicular trafficking in eukaryotes. Analysis of the rice genome revealed 20 putative 5PTases including D50. The d50 mutation induced abnormally oriented cell division, irregular deposition of cell wall pectins and thick actin bundles in the parenchyma cells of the IM, resulting in abnormally organized cell files of the internode parenchyma and dwarf phenotype. Our results suggest that the putative 5PTase, encoded by D50, is essential for IM formation, including the direction of cell division, deposition of cell wall pectins and control of actin organization.
authors.affiliation: Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan. ikanna@cc.tuat.ac.jp
authors.forename: Kanna
authors.initials: K
authors.lastname: Sato-Izawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakaba
authors.forename: Katsunori
authors.initials: K
authors.lastname: Tamura
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yamagishi
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Nakano
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Nishikubo
authors.forename: Shinya
authors.initials: S
authors.lastname: Kawai
authors.forename: Shinya
authors.initials: S
authors.lastname: Kajita
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Ashikari
authors.forename: Ryo
authors.initials: R
authors.lastname: Funada
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Katayama
authors.forename: Hidemi
authors.initials: H
authors.lastname: Kitano
mesh_terms: D000199:Actins / Q000378:metabolism / Q000648:ultrastructure; D000595:Amino Acid Sequence; D002455:Cell Division / Q000235:genetics; D048430:Cell Shape; D002473:Cell Wall / Q000378:metabolism; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D000072181:Inositol Polyphosphate 5-Phosphatases; D018519:Meristem / Q000235:genetics*; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D010368:Pectins / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016415:Sequence Alignment
chemical_list: D000199:Actins; D010940:Plant Proteins; D010368:Pectins; D010744:Phosphoric Monoester Hydrolases; D000072181:Inositol Polyphosphate 5-Phosphatases