ydk1-D, an auxin-responsive GH3 mutant that is involved in hypocotyl and root elongation

Plant J. 2004 Feb;37(4):471-83. doi: 10.1046/j.1365-313x.2003.01973.x.


To study the GH3 gene family of Arabidopsis, we investigated a flanking sequence database of Arabidopsis activation-tagged lines. We found a dwarf mutant, named yadokari 1-D (ydk1-D), that had a T-DNA insertion proximal to a GH3 gene. ydk1-D is dominant and has a short hypocotyl not only in light but also in darkness. Moreover, ydk1-D has a short primary root, a reduced lateral root number, and reduced apical dominance. A GH3 gene, named YDK1, was upregulated in ydk1-D, and YDK1 transgenic plants showed the ydk1-D phenotype. YDK1 gene expression was induced by exogenously applied auxin and regulated by auxin-response factor (ARF)7. In addition, YDK1 gene expression was downregulated by blue and far-red (FR) lights. Strong promoter activity of YDK1 was observed in roots and flowers. These results suggest that YDK1 may function as a negative component in auxin signaling by regulating auxin activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / drug effects
  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Gene Expression Regulation, Developmental / drug effects
  • Gene Expression Regulation, Developmental / radiation effects
  • Gene Expression Regulation, Plant / drug effects
  • Gene Expression Regulation, Plant / radiation effects
  • Hypocotyl / drug effects
  • Hypocotyl / genetics
  • Hypocotyl / growth & development*
  • Indoleacetic Acids / pharmacology*
  • Light
  • Multigene Family
  • Phenotype
  • Plant Growth Regulators / genetics
  • Plant Growth Regulators / metabolism
  • Plant Growth Regulators / pharmacology
  • Plant Roots / drug effects
  • Plant Roots / genetics
  • Plant Roots / growth & development*
  • Plants, Genetically Modified


  • Arabidopsis Proteins
  • DFL1 protein, Arabidopsis
  • DFL2 protein, Arabidopsis
  • Indoleacetic Acids
  • Plant Growth Regulators
  • YDK1 protein, Arabidopsis