Tissue layer specific regulation of leaf length and width in Arabidopsis as revealed by the cell autonomous action of ANGUSTIFOLIA

Plant J. 2010 Jan;61(2):191-9. doi: 10.1111/j.1365-313X.2009.04050.x. Epub 2009 Oct 16.


In vascular plants the shoot apical meristem consists of three tissue layers, L1, L2 and the L3, that are kept separate during organ formation and give rise to the epidermis (L1) and the subepidermal tissues (L2, L3). For proper organ development these different tissue layers must interact with each other, though their relative contributions are a matter of debate. Here we use ANGUSTIFOLIA (AN), which controls cell polarity and leaf shape, to study its morphogenetic function in the epidermis and the subepidermis of Arabidopsis thaliana. We show that ANGUSTIFOLIA expression in the subepidermis cannot rescue epidermal cell polarity defects, indicating a cell-autonomous molecular function. We demonstrate that leaf width is only rescued by subepidermal AN expression, whereas leaf length is also rescued by epidermal expression. Strikingly, subepidermal rescue of leaf width is accompanied by increased cell number in the epidermis, indicating that AN can trigger cell divisions in a non-autonomous manner.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / cytology
  • Arabidopsis / genetics*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Arabidopsis Proteins / physiology
  • Cell Division
  • Gene Expression Regulation, Plant
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Meristem / cytology
  • Meristem / genetics
  • Mutation
  • Plant Epidermis / cytology
  • Plant Epidermis / genetics
  • Plant Leaves / cytology
  • Plant Leaves / genetics*
  • Plant Leaves / physiology
  • Plants, Genetically Modified
  • Repressor Proteins / genetics*
  • Repressor Proteins / metabolism
  • Repressor Proteins / physiology
  • Reverse Transcriptase Polymerase Chain Reaction


  • ANGUSTIFOLIA protein, Arabidopsis
  • Arabidopsis Proteins
  • Repressor Proteins
  • Green Fluorescent Proteins