Expression of the Arabidopsis abi1-1 mutant allele inhibits proteinase inhibitor wound-induction in tomato

Plant J. 1998 Sep;15(6):765-71. doi: 10.1046/j.1365-313x.1998.00261.x.

Abstract

Abscisic acid (ABA) is an essential component in the wound signalling cascade. Increased levels of endogenous ABA were observed after wounding and shown to be a requisite for wound-induced expression of the proteinase inhibitor II genes. We have taken advantage of the dominant character of the Arabidopsis abi1-1 mutation, to investigate whether ABl1 has a function in ABA signalling in response to wounding. Transgenic tomato plants carrying copies of either the wild-type ABI1 or the mutant abi1-1 alleles were obtained and assayed for wound-induction of the pin2 or LAP genes. While normal levels of gene induction were observed in the transgenic ABI1 plants, the abi1-1 transformants displayed a severe wilty phenotype and reduced seed dormancy. Expression of the abi1-1 dominant mutation blocked accumulation of the drought-induced TAS14 and LE25 mRNAs in response to ABA, as well as ABA- and wound-induced expression of the defense-associated pin2 and LAP transcripts. MeJA-induction of the pin2 and LAP mRNAs, on the contrary, was not affected in the abi1-1 transformants. These results indicate that abi1-1 inhibits wound-induced expression of the pin2 and LAP transcripts by blocking ABA-induction of these genes. This implicates ABI1 in wound-signalling and suggests that a common early ABA signalling pathway may function in the responses to wounding and water stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Arabidopsis / genetics*
  • Arabidopsis Proteins*
  • CCAAT-Enhancer-Binding Proteins
  • DNA-Binding Proteins / genetics
  • Gene Expression Regulation, Plant*
  • Lycopersicon esculentum
  • Mutation*
  • Nuclear Proteins / genetics
  • Phenotype
  • Phosphoprotein Phosphatases / genetics*
  • Plant Diseases*
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Protease Inhibitors / metabolism*
  • Signal Transduction / genetics
  • Transcriptional Activation
  • Transfection

Substances

  • Arabidopsis Proteins
  • CCAAT-Enhancer-Binding Proteins
  • DNA-Binding Proteins
  • Nuclear Proteins
  • Plant Proteins
  • Protease Inhibitors
  • proteinase inhibitor II protein, plant
  • ABI1 protein, Arabidopsis
  • Phosphoprotein Phosphatases