A bHLH complex controls embryonic vascular tissue establishment and indeterminate growth in Arabidopsis

Dev Cell. 2013 Feb 25;24(4):426-37. doi: 10.1016/j.devcel.2012.12.013. Epub 2013 Feb 14.


Plants have a remarkable potential for sustained (indeterminate) postembryonic growth. Following their specification in the early embryo, tissue-specific precursor cells first establish tissues and later maintain them postembryonically. The mechanisms underlying these processes are largely unknown. Here we define local control of oriented, periclinal cell division as the mechanism underlying both the establishment and maintenance of vascular tissue. We identify an auxin-regulated basic helix-loop-helix (bHLH) transcription factor dimer as a critical regulator of vascular development. Due to a loss of periclinal divisions, vascular tissue gradually disappears in bHLH-deficient mutants; conversely, ectopic expression is sufficient for triggering periclinal divisions. We show that this dimer operates independently of tissue identity but is restricted to a small vascular domain by integrating overlapping transcription patterns of the interacting bHLH proteins. Our work reveals a common mechanism for tissue establishment and indeterminate vascular development and provides a conceptual framework for developmental control of local cell divisions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / embryology*
  • Arabidopsis / genetics
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Blotting, Western
  • Cell Differentiation
  • Cell Division
  • Fluorescence Resonance Energy Transfer
  • Gene Expression Regulation, Plant*
  • Immunoprecipitation
  • Indoleacetic Acids / pharmacology
  • Meristem / cytology*
  • Mutation / genetics
  • Plant Development / drug effects
  • Plant Development / physiology*
  • Plants, Genetically Modified / embryology
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism
  • Protein Multimerization
  • Protein Structure, Tertiary
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction


  • Arabidopsis Proteins
  • Basic Helix-Loop-Helix Transcription Factors
  • Indoleacetic Acids
  • RNA, Messenger