The RETINOBLASTOMA-RELATED gene regulates stem cell maintenance in Arabidopsis roots.
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.
Wildwater
Marjolein
M
Department of Molecular Cell Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Campilho
Ana
A
Perez-Perez
Jose Manuel
JM
Heidstra
Renze
R
Blilou
Ikram
I
Korthout
Henrie
H
Chatterjee
Jayanta
J
Mariconti
Luisa
L
Gruissem
Wilhelm
W
Scheres
Ben
B
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*
D029681:Arabidopsis Proteins; C487568:RBR1 protein, Arabidopsis; D016160:Retinoblastoma Protein