Root growth is modulated by differential hormonal sensitivity in neighboring cells

Genes Dev. 2014 Apr 15;28(8):912-20. doi: 10.1101/gad.239335.114.

Abstract

Coherent plant growth requires spatial integration of hormonal pathways and cell wall remodeling activities. However, the mechanisms governing sensitivity to hormones and how cell wall structure integrates with hormonal effects are poorly understood. We found that coordination between two types of epidermal root cells, hair and nonhair cells, establishes root sensitivity to the plant hormones brassinosteroids (BRs). While expression of the BR receptor BRASSINOSTEROID-INSENSITIVE1 (BRI1) in hair cells promotes cell elongation in all tissues, its high relative expression in nonhair cells is inhibitory. Elevated ethylene and deposition of crystalline cellulose underlie the inhibitory effect of BRI1. We propose that the relative spatial distribution of BRI1, and not its absolute level, fine-tunes growth.

Keywords: brassinosteroids; cell size determination; cell wall; hormone signaling; intercellular communication; root development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / cytology
  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Brassinosteroids / metabolism*
  • Cell Enlargement
  • Cellulose / metabolism
  • Ethylenes / metabolism
  • Gene Expression Regulation, Plant
  • Plant Roots / cytology
  • Plant Roots / growth & development*
  • Plant Roots / metabolism
  • Protein Kinases / genetics

Substances

  • Arabidopsis Proteins
  • Brassinosteroids
  • Ethylenes
  • Cellulose
  • ethylene
  • Protein Kinases
  • BRI1 protein, Arabidopsis