title: The RETINOBLASTOMA-RELATED gene regulates stem cell maintenance in Arabidopsis roots.
abstract: The maintenance of stem cells in defined locations is crucial for all multicellular organisms. Although intrinsic factors and signals for stem cell fate have been identified in several species, it has remained unclear how these connect to the ability to reenter the cell cycle that is one of the defining properties of stem cells. We show that local reduction of expression of the RETINOBLASTOMA-RELATED (RBR) gene in Arabidopsis roots increases the amount of stem cells without affecting cell cycle duration in mitotically active cells. Conversely, induced RBR overexpression dissipates stem cells prior to arresting other mitotic cells. Overexpression of D cyclins, KIP-related proteins, and E2F factors also affects root stem cell pool size, and genetic interactions suggest that these factors function in a canonical RBR pathway to regulate somatic stem cells. Expression analysis and genetic interactions position RBR-mediated regulation of the stem cell state downstream of the patterning gene SCARECROW.
authors.affiliation: Department of Molecular Cell Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: Marjolein
authors.initials: M
authors.lastname: Wildwater
authors.forename: Ana
authors.initials: A
authors.lastname: Campilho
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: Perez-Perez
authors.forename: Renze
authors.initials: R
authors.lastname: Heidstra
authors.forename: Ikram
authors.initials: I
authors.lastname: Blilou
authors.forename: Henrie
authors.initials: H
authors.lastname: Korthout
authors.forename: Jayanta
authors.initials: J
authors.lastname: Chatterjee
authors.forename: Luisa
authors.initials: L
authors.lastname: Mariconti
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Gruissem
authors.forename: Ben
authors.initials: B
authors.lastname: Scheres
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D015536:Down-Regulation; D018517:Plant Roots / Q000166:cytology* / Q000254:growth & development* / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C487568:RBR1 protein, Arabidopsis; D016160:Retinoblastoma Protein