Plant Stress Tolerance Requires Auxin-Sensitive Aux/IAA Transcriptional Repressors

Curr Biol. 2017 Feb 6;27(3):437-444. doi: 10.1016/j.cub.2016.12.016. Epub 2017 Jan 19.


The Aux/IAA proteins are auxin-sensitive repressors that mediate diverse physiological and developmental processes in plants [1, 2]. There are 29 Aux/IAA genes in Arabidopsis that exhibit unique but partially overlapping patterns of expression [3]. Although some studies have suggested that individual Aux/IAA genes have specialized function, genetic analyses of the family have been limited by the scarcity of loss-of-function phenotypes [4]. Furthermore, with a few exceptions, our knowledge of the factors that regulate Aux/IAA expression is limited [1, 5]. We hypothesize that transcriptional control of Aux/IAA genes plays a central role in the establishment of the auxin-signaling pathways that regulate organogenesis, growth, and environmental response. Here, we describe a screen for transcription factors (TFs) that regulate the Aux/IAA genes. We identify TFs from 38 families, including 26 members of the DREB/CBF family. Several DREB/CBF TFs directly promote transcription of the IAA5 and IAA19 genes in response to abiotic stress. Recessive mutations in these IAA genes result in decreased tolerance to stress conditions, demonstrating a role for auxin in abiotic stress. Our results demonstrate that stress pathways interact with the auxin gene regulatory network (GRN) through transcription of the Aux/IAA genes. We propose that the Aux/IAA genes function as hubs that integrate genetic and environmental information to achieve the appropriate developmental or physiological outcome.

Keywords: Aux/IAA; abiotic stress; auxin; plant hormone; repressor.

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / antagonists & inhibitors
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Gene Expression Regulation, Plant / drug effects*
  • Indoleacetic Acids / metabolism
  • Plant Growth Regulators / metabolism
  • Plants, Genetically Modified
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Stress, Physiological


  • Arabidopsis Proteins
  • Indoleacetic Acids
  • Plant Growth Regulators
  • Repressor Proteins