Abstract

The plant hormone auxin (indole-3-acetic acid, IAA) has a crucial role in plant development. Its spatiotemporal distribution is controlled by a combination of biosynthetic, metabolic and transport mechanisms. Four families of auxin transporters have been identified that mediate transport across the plasma or endoplasmic reticulum membrane. Here we report the discovery and the functional characterization of the first vacuolar auxin transporter. We demonstrate that WALLS ARE THIN1 (WAT1), a plant-specific protein that dictates secondary cell wall thickness of wood fibres, facilitates auxin export from isolated Arabidopsis vacuoles in yeast and in Xenopus oocytes. We unambiguously identify IAA and related metabolites in isolated Arabidopsis vacuoles, suggesting a key role for the vacuole in intracellular auxin homoeostasis. Moreover, local auxin application onto wat1 mutant stems restores fibre cell wall thickness. Our study provides new insight into the complexity of auxin transport in plants and a means to dissect auxin function during fibre differentiation.

Published in

Nature Communications
2013, Volume: 4, article number: 2625
Publisher: NATURE PUBLISHING GROUP

SLU Authors

• Lundberg-Felten, Judith

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Novak, Ondrej

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    
  • Palacký University Olomouc

• Jin, Xu

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Ljung, Karin

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Fischer, Urs

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Developmental Biology


Publication identifier

DOI: https://doi.org/10.1038/ncomms3625

Permanent link to this page (URI)

https://res.slu.se/id/publ/52465