TIR1/AFB-Aux/IAA auxin perception mediates rapid cell wall acidification and growth of Arabidopsis hypocotyls

  1. Matyáš Fendrych
  2. Jeffrey Leung
  3. Jiří Friml  Is a corresponding author
  1. Institute of Science and Technology Austria, Austria
  2. Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, France


Despite being composed of immobile cells, plants reorient along directional stimuli. The hormone auxin is redistributed in stimulated organs leading to differential growth and bending. Auxin application triggers rapid cell wall acidification and elongation of aerial organs of plants, but the molecular players mediating these effects are still controversial. Here we use genetically-encoded pH and auxin signaling sensors, pharmacological and genetic manipulations available for Arabidopsis etiolated hypocotyls to clarify how auxin is perceived and the downstream growth executed. We show that auxin-induced acidification occurs by local activation of H+-ATPases, which in the context of gravity response is restricted to the lower organ side. This auxin-stimulated acidification and growth require TIR1/AFB-Aux/IAA nuclear auxin perception. In addition, auxin-induced gene transcription and specifically SAUR proteins are crucial downstream mediators of this growth. Our study provides strong experimental support for the acid growth theory and clarified the contribution of the upstream auxin perception mechanisms.

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Author details

  1. Matyáš Fendrych

    Institute of Science and Technology Austria, Klosterneuburg, Austria
    Competing interests
    The authors declare that no competing interests exist.
  2. Jeffrey Leung

    Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, Versailles, France
    Competing interests
    The authors declare that no competing interests exist.
  3. Jiří Friml

    Institute of Science and Technology Austria, Klosterneuburg, Austria
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8302-7596


European Research Council (project ERC-2011-StG-20101109-PSDP)

  • Jiří Friml

Marie Curie Actions FP7 2007-2013 (REA grant agreement n.291734)

  • Matyáš Fendrych

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Gary Stacey, University of Missouri, United States

Publication history

  1. Received: June 22, 2016
  2. Accepted: September 13, 2016
  3. Accepted Manuscript published: September 14, 2016 (version 1)
  4. Version of Record published: September 30, 2016 (version 2)
  5. Version of Record updated: January 10, 2018 (version 3)


© 2016, Fendrych et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.


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  1. Matyáš Fendrych
  2. Jeffrey Leung
  3. Jiří Friml
TIR1/AFB-Aux/IAA auxin perception mediates rapid cell wall acidification and growth of Arabidopsis hypocotyls
eLife 5:e19048.

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