Auxin regulates aquaporin function to facilitate lateral root emergence

Nat Cell Biol. 2012 Oct;14(10):991-8. doi: 10.1038/ncb2573. Epub 2012 Sep 16.


Aquaporins are membrane channels that facilitate water movement across cell membranes. In plants, aquaporins contribute to water relations. Here, we establish a new link between aquaporin-dependent tissue hydraulics and auxin-regulated root development in Arabidopsis thaliana. We report that most aquaporin genes are repressed during lateral root formation and by exogenous auxin treatment. Auxin reduces root hydraulic conductivity both at the cell and whole-organ levels. The highly expressed aquaporin PIP2;1 is progressively excluded from the site of the auxin response maximum in lateral root primordia (LRP) whilst being maintained at their base and underlying vascular tissues. Modelling predicts that the positive and negative perturbations of PIP2;1 expression alter water flow into LRP, thereby slowing lateral root emergence (LRE). Consistent with this mechanism, pip2;1 mutants and PIP2;1-overexpressing lines exhibit delayed LRE. We conclude that auxin promotes LRE by regulating the spatial and temporal distribution of aquaporin-dependent root tissue water transport.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aquaporins / genetics
  • Aquaporins / physiology*
  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis Proteins / metabolism
  • Biological Transport / genetics
  • Biological Transport / physiology
  • Gene Expression Regulation, Plant
  • Gene Silencing
  • Indoleacetic Acids / metabolism*
  • Models, Biological
  • Mutation
  • Plant Roots / genetics
  • Plant Roots / growth & development*
  • Transcription Factors / metabolism
  • Water / physiology


  • ARF7 protein, Arabidopsis
  • Aquaporins
  • Arabidopsis Proteins
  • Indoleacetic Acids
  • Transcription Factors
  • Water