Organizer-Derived WOX5 Signal Maintains Root Columella Stem Cells Through Chromatin-Mediated Repression of CDF4 Expression

Dev Cell. 2015 Jun 8;33(5):576-88. doi: 10.1016/j.devcel.2015.04.024. Epub 2015 May 28.

Abstract

Stem cells in plants and animals are maintained pluripotent by signals from adjacent niche cells. In plants, WUSCHEL HOMEOBOX (WOX) transcription factors are central regulators of stem cell maintenance in different meristem types, yet their molecular mode of action has remained elusive. Here we show that in the Arabidopsis root meristem, the WOX5 protein moves from the root niche organizer, the quiescent center, into the columella stem cells, where it directly represses the transcription factor gene CDF4. This creates a gradient of CDF4 transcription, which promotes differentiation opposite to the WOX5 gradient, allowing stem cell daughter cells to exit the stem cell state. We further show that WOX5 represses CDF4 transcription by recruiting TPL/TPR co-repressors and the histone deacetylase HDA19, which consequently induces histone deacetylation at the CDF4 regulatory region. Our results show that chromatin-mediated repression of differentiation programs is a common strategy in plant and animal stem cell niches.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Cell Differentiation*
  • Chromatin / genetics*
  • Chromatin Immunoprecipitation
  • Co-Repressor Proteins / genetics
  • Co-Repressor Proteins / metabolism
  • Electrophoretic Mobility Shift Assay
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Plant
  • Histone Deacetylases / genetics
  • Histone Deacetylases / metabolism
  • Histones / metabolism
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • In Situ Hybridization
  • Meristem / cytology*
  • Meristem / metabolism
  • Microarray Analysis
  • Microscopy, Confocal
  • Nuclear Pore Complex Proteins / genetics
  • Nuclear Pore Complex Proteins / metabolism
  • Plant Roots / cytology*
  • Plant Roots / metabolism
  • Promoter Regions, Genetic / genetics
  • Signal Transduction
  • Stem Cell Niche
  • Stem Cells / cytology*
  • Stem Cells / metabolism

Substances

  • Arabidopsis Proteins
  • Chromatin
  • Co-Repressor Proteins
  • Histones
  • Homeodomain Proteins
  • Nuclear Pore Complex Proteins
  • TPR protein, Arabidopsis
  • WUSCHEL protein, Arabidopsis
  • topless protein, Arabidopsis
  • HDA19 protein, Arabidopsis
  • Histone Deacetylases