Abstract
Quiescent long-term somatic stem cells reside in plant and animal stem cell niches. Within the Arabidopsis root stem cell population, the Quiescent Centre (QC), which contains slowly dividing cells, maintains surrounding short-term stem cells and may act as a long-term reservoir for stem cells. The RETINOBLASTOMA-RELATED (RBR) protein cell-autonomously reinforces mitotic quiescence in the QC. RBR interacts with the stem cell transcription factor SCARECROW (SCR) through an LxCxE motif. Disruption of this interaction by point mutation in SCR or RBR promotes asymmetric divisions in the QC that renew short-term stem cells. Analysis of the in vivo role of quiescence in the root stem cell niche reveals that slow cycling within the QC is not needed for structural integrity of the niche but allows the growing root to cope with DNA damage.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Arabidopsis / cytology*
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Arabidopsis / metabolism
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Arabidopsis Proteins / chemistry
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Arabidopsis Proteins / metabolism*
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Cell Proliferation
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Gene Knockdown Techniques
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Meristem / cytology*
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Meristem / metabolism
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Protein Binding
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Protein Interaction Domains and Motifs
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Protein Interaction Maps
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Stem Cell Niche
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Stem Cells / physiology
Substances
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Arabidopsis Proteins
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RBR1 protein, Arabidopsis
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SCR protein, Arabidopsis
Grants and funding
AC-R was supported by European Molecular Biology Long Term Fellowship (EMBO-ALTF 1114-2006); Consejo Nacional de Ciencia y Tecnología, México (CONACYT No. Reg.000000000092916); and NGI-NPC II grants. SD-T was funded by Ministerio de Educacion y Ciencia, Spain; Marie Curie IEF (IEF-2008-237643); by EU Advanced Grant SysArc; and by the NIRM consortium for stem cell research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.