Functional genomic analysis of the AUXIN/INDOLE-3-ACETIC ACID gene family members in Arabidopsis thaliana

Plant Cell. 2005 Dec;17(12):3282-300. doi: 10.1105/tpc.105.036723. Epub 2005 Nov 11.


Auxin regulates various aspects of plant growth and development. The AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) genes encode short-lived transcriptional repressors that are targeted by the TRANSPORT INHIBITOR RESPONSE1/AUXIN RECEPTOR F-BOX proteins. The Aux/IAA proteins regulate auxin-mediated gene expression by interacting with members of the AUXIN RESPONSE FACTOR protein family. Aux/IAA function is poorly understood; herein, we report the identification and characterization of insertion mutants in 12 of the 29 Aux/IAA family members. The mutants show no visible developmental defects compared with the wild type. Double or triple mutants of closely related Aux/IAA genes, such as iaa8-1 iaa9-1 or iaa5-1 iaa6-1 iaa19-1, also exhibit wild-type phenotypes. Global gene expression analysis reveals that the molecular phenotypes of auxin-treated and untreated light-grown seedlings are unaffected in the iaa17-6 and iaa5-1 iaa6-1 iaa19-1 mutants. By contrast, similar analysis with the gain-of-function axr3-1/iaa17-1 mutant seedlings reveals dramatic changes in basal and auxin-induced gene expression compared with the wild type. Expression of several type-A ARABIDOPSIS RESPONSE REGULATOR genes and a number of genes involved in cell wall biosynthesis and degradation is repressed in axr3-1/iaa17-1. The data suggest extensive functional redundancy among Aux/IAA gene family members and that enhanced stability of the AXR3/IAA17 protein severely alters the molecular phenotype, resulting in developmental defects.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Gene Expression Regulation, Plant / genetics
  • Genome, Plant*
  • Indoleacetic Acids / chemistry
  • Indoleacetic Acids / metabolism*
  • Molecular Sequence Data
  • Multigene Family*
  • Mutagenesis, Insertional
  • Sequence Homology, Amino Acid


  • Indoleacetic Acids
  • indoleacetic acid

Associated data

  • GENBANK/AY669797
  • GENBANK/AY669798
  • GENBANK/AY669799
  • GENBANK/AY669800
  • GENBANK/AY669801
  • GENBANK/AY669802
  • GENBANK/AY669803
  • GENBANK/AY669804
  • OMIM/GSE629
  • OMIM/GSM9595
  • OMIM/GSM9596
  • OMIM/GSM9597
  • OMIM/GSM9598
  • OMIM/GSM9599
  • OMIM/GSM9600
  • OMIM/GSM9601
  • OMIM/GSM9602
  • OMIM/GSM9603
  • OMIM/GSM9605
  • OMIM/GSM9606
  • OMIM/GSM9607
  • OMIM/GSM9608
  • OMIM/GSM9609
  • OMIM/GSM9610
  • OMIM/GSM9611
  • OMIM/GSM9612
  • OMIM/GSM9613
  • OMIM/GSM9614
  • OMIM/GSM9615
  • OMIM/GSM9616
  • OMIM/GSM9617
  • OMIM/GSM9618
  • OMIM/GSM9619