Ethylene stimulates nutations that are dependent on the ETR1 receptor

Plant Physiol. 2006 Dec;142(4):1690-700. doi: 10.1104/pp.106.087858. Epub 2006 Oct 27.

Abstract

Ethylene influences a number of processes in Arabidopsis (Arabidopsis thaliana) through the action of five receptors. In this study, we used high-resolution, time-lapse imaging to examine the long-term effects of ethylene on growing, etiolated Arabidopsis seedlings. These measurements revealed that ethylene stimulates nutations of the hypocotyls with an average delay in onset of over 6 h. The nutation response was constitutive in ctr1-2 mutants maintained in air, whereas ein2-1 mutants failed to nutate when treated with ethylene. Ethylene-stimulated nutations were also eliminated in etr1-7 loss-of-function mutants. Transformation of the etr1-7 mutant with a wild-type genomic ETR1 transgene rescued the nutation phenotype, further supporting a requirement for ETR1. Loss-of-function mutations in the other receptor isoforms had no effect on ethylene-stimulated nutations. However, the double ers1-2 ers2-3 and triple etr2-3 ers2-3 ein4-4 loss-of-function mutants constitutively nutated in air. These results support a model where all the receptors are involved in ethylene-stimulated nutations, but the ETR1 receptor is required and has a contrasting role from the other receptor isoforms in this nutation phenotype. Naphthylphthalamic acid eliminated ethylene-stimulated nutations but had no effect on growth inhibition caused by ethylene, pointing to a role for auxin transport in the nutation phenotype.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Arabidopsis / drug effects*
  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / physiology*
  • Ethylenes / pharmacology*
  • Indoleacetic Acids / metabolism
  • Mutation
  • Phenotype
  • Plant Growth Regulators / pharmacology*
  • Protein Isoforms / genetics
  • Protein Isoforms / physiology
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / physiology*
  • Seedlings / drug effects
  • Seedlings / genetics
  • Seedlings / growth & development
  • Signal Transduction / drug effects
  • Transformation, Genetic
  • Transgenes

Substances

  • Arabidopsis Proteins
  • ETR1 protein, Arabidopsis
  • Ethylenes
  • Indoleacetic Acids
  • Plant Growth Regulators
  • Protein Isoforms
  • Receptors, Cell Surface
  • ethylene