Auxin and epigenetic regulation of SKP2B, an F-box that represses lateral root formation

Plant Physiol. 2012 Oct;160(2):749-62. doi: 10.1104/pp.112.198341. Epub 2012 Jul 26.

Abstract

In plants, lateral roots originate from pericycle founder cells that are specified at regular intervals along the main root. Here, we show that Arabidopsis (Arabidopsis thaliana) SKP2B (for S-Phase Kinase-Associated Protein2B), an F-box protein, negatively regulates cell cycle and lateral root formation as it represses meristematic and founder cell divisions. According to its function, SKP2B is expressed in founder cells, lateral root primordia and the root apical meristem. We identified a novel motif in the SKP2B promoter that is required for its specific root expression and auxin-dependent induction in the pericycle cells. Next to a transcriptional control by auxin, SKP2B expression is regulated by histone H3.1/H3.3 deposition in a CAF-dependent manner. The SKP2B promoter and the 5' end of the transcribed region are enriched in H3.3, which is associated with active chromatin states, over H3.1. Furthermore, the SKP2B promoter is also regulated by H3 acetylation in an auxin- and IAA14-dependent manner, reinforcing the idea that epigenetics represents an important regulatory mechanism during lateral root formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Arabidopsis / drug effects
  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cell Division
  • Chromatin Immunoprecipitation
  • Epigenesis, Genetic*
  • F-Box Proteins / genetics
  • F-Box Proteins / metabolism*
  • Gene Expression Regulation, Plant
  • Histones / genetics
  • Histones / metabolism
  • Indoleacetic Acids / pharmacology
  • Meristem / drug effects
  • Meristem / genetics
  • Meristem / growth & development
  • Plant Growth Regulators / metabolism
  • Plant Growth Regulators / pharmacology
  • Plant Roots / drug effects
  • Plant Roots / genetics
  • Plant Roots / growth & development*
  • Promoter Regions, Genetic
  • S-Phase Kinase-Associated Proteins / genetics
  • S-Phase Kinase-Associated Proteins / metabolism*
  • Signal Transduction
  • Transcription, Genetic

Substances

  • Arabidopsis Proteins
  • F-Box Proteins
  • Histones
  • Indoleacetic Acids
  • Plant Growth Regulators
  • S-Phase Kinase-Associated Proteins