Auxin receptors and plant development: a new signaling paradigm

Annu Rev Cell Dev Biol. 2008:24:55-80. doi: 10.1146/annurev.cellbio.23.090506.123214.


The plant hormone auxin, in particular indole-3-acetic acid (IAA), is a key regulator of virtually every aspect of plant growth and development. Auxin regulates transcription by rapidly modulating levels of Aux/IAA proteins throughout development. Recent studies demonstrate that auxin perception occurs through a novel mechanism. Auxin binds to TIR1, the F-box subunit of the ubiquitin ligase complex SCF(TIR1), and stabilizes the interaction between TIR1 and Aux/IAA substrates. This interaction results in Aux/IAA ubiquitination and subsequent degradation. Regulation of the Aux/IAA protein family by TIR1 and TIR1-like auxin receptors (AFBs) links auxin action to transcriptional regulation and provides a model by which the vast array of auxin influences on development may be understood. Moreover, auxin receptor function is the first example of small-molecule regulation of an SCF ubiquitin ligase and may have important implications for studies of regulated protein degradation in other species, including animals.

Publication types

  • Review

MeSH terms

  • Animals
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / metabolism
  • F-Box Proteins / chemistry
  • F-Box Proteins / metabolism
  • Gene Expression Regulation, Plant
  • Indoleacetic Acids / metabolism*
  • Models, Molecular
  • Plant Development*
  • Plant Growth Regulators / metabolism*
  • Plant Proteins / chemistry
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plants / metabolism
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Conformation
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism*
  • SKP Cullin F-Box Protein Ligases / metabolism
  • Signal Transduction / physiology*
  • Transcription Factors / metabolism
  • Transcription, Genetic
  • Ubiquitin / metabolism


  • Arabidopsis Proteins
  • F-Box Proteins
  • Indoleacetic Acids
  • Plant Growth Regulators
  • Plant Proteins
  • Receptors, Cell Surface
  • TIR1 protein, Arabidopsis
  • Transcription Factors
  • Ubiquitin
  • auxin receptor, plant
  • indoleacetic acid
  • SKP Cullin F-Box Protein Ligases
  • Proteasome Endopeptidase Complex