Auxin controls Arabidopsis adventitious root initiation by regulating jasmonic acid homeostasis

Plant Cell. 2012 Jun;24(6):2515-27. doi: 10.1105/tpc.112.099119. Epub 2012 Jun 22.

Abstract

Vegetative shoot-based propagation of plants, including mass propagation of elite genotypes, is dependent on the development of shoot-borne roots, which are also called adventitious roots. Multiple endogenous and environmental factors control the complex process of adventitious rooting. In the past few years, we have shown that the auxin response factors ARF6 and ARF8, targets of the microRNA miR167, are positive regulators of adventitious rooting, whereas ARF17, a target of miR160, is a negative regulator. We showed that these genes have overlapping expression profiles during adventitious rooting and that they regulate each other's expression at the transcriptional and posttranscriptional levels by modulating the homeostasis of miR160 and miR167. We demonstrate here that this complex network of transcription factors regulates the expression of three auxin-inducible Gretchen Hagen3 (GH3) genes, GH3.3, GH3.5, and GH3.6, encoding acyl-acid-amido synthetases. We show that these three GH3 genes are required for fine-tuning adventitious root initiation in the Arabidopsis thaliana hypocotyl, and we demonstrate that they act by modulating jasmonic acid homeostasis. We propose a model in which adventitious rooting is an adaptive developmental response involving crosstalk between the auxin and jasmonate regulatory pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / metabolism
  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Cyclopentanes / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Plant
  • Homeostasis
  • Hypocotyl / genetics
  • Hypocotyl / metabolism
  • Indoleacetic Acids / metabolism*
  • Ligases / genetics*
  • Ligases / metabolism
  • Mutation
  • Oxylipins / metabolism*
  • Plant Roots / growth & development*
  • Plant Roots / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Amino Acids
  • Arabidopsis Proteins
  • CONSTANS protein, Arabidopsis
  • Cyclopentanes
  • DNA-Binding Proteins
  • Indoleacetic Acids
  • Oxylipins
  • Transcription Factors
  • jasmonic acid
  • GH3.5 protein, Arabidopsis
  • Ligases