title: The Arabidopsis OBERON1 and OBERON2 genes encode plant homeodomain finger proteins and are required for apical meristem maintenance.
abstract: Maintenance of the stem cell population located at the apical meristems is essential for repetitive organ initiation during the development of higher plants. Here, we have characterized the roles of OBERON1 (OBE1) and its paralog OBERON2 (OBE2), which encode plant homeodomain finger proteins, in the maintenance and/or establishment of the meristems in Arabidopsis. Although the obe1 and obe2 single mutants were indistinguishable from wild-type plants, the obe1 obe2 double mutant displayed premature termination of the shoot meristem, suggesting that OBE1 and OBE2 function redundantly. Further analyses revealed that OBE1 and OBE2 allow the plant cells to acquire meristematic activity via the WUSCHEL-CLAVATA pathway, which is required for the maintenance of the stem cell population, and they function parallel to the SHOOT MERISTEMLESS gene, which is required for preventing cell differentiation in the shoot meristem. In addition, obe1 obe2 mutants failed to establish the root apical meristem, lacking both the initial cells and the quiescent center. In situ hybridization revealed that expression of PLETHORA and SCARECROW, which are required for stem cell specification and maintenance in the root meristem, was lost from obe1 obe2 mutant embryos. Taken together, these data suggest that the OBE1 and OBE2 genes are functionally redundant and crucial for the maintenance and/or establishment of both the shoot and root meristems.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo, Tokyo 113-0033, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Saiga
authors.forename: Chihiro
authors.initials: C
authors.lastname: Furumizu
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Yokoyama
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kurata
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Kato
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Suzuki
authors.forename: Yoshibumi
authors.initials: Y
authors.lastname: Komeda
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D018519:Meristem / Q000254:growth & development / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D018517:Plant Roots / Q000378:metabolism; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; C530857:Oberon1 protein, Arabidopsis; C530858:Oberon2 protein, Arabidopsis