Generation of dominant-negative effects on the heat shock response in Arabidopsis thaliana by transgenic expression of a chimaeric HSF1 protein fusion construct

Plant J. 2003 Aug;35(4):442-51. doi: 10.1046/j.1365-313x.2003.01815.x.


Upon heat stress, heat shock factors (HSFs) control the expression of heat shock protein (HSP) genes by transcriptional activation. The perplexing multiplicity of HSF genes in Arabidopsis- 21 potential genes have been identified - renders it difficult to identify mutant phenotypes. In this study, we have attempted to generate a transdominant-negative mutant of HSF by transgenic expression of a protein fusion construct, EN-HSF1, consisting of the Drosophila engrailed repressor domain (EN) and the complete Arabidopsis AtHSF1. Transgenic lines were screened for impaired ability to induce high levels of low-molecular-weight heat shock proteins (sHSPs). Two lines, EH14-6 and EH16-3, which showed quantitative differences in the expression of EN-HSF1, were further analysed for induction of thermotolerance and heat-stress-dependent mRNAs of a number of different HSF target genes encoding different HSP and HSF. The mRNA levels of all genes tested were moderately downregulated in EH14-6 but strongly reduced in EH16-3 plants compared to wild-type (Wt) and HSF1-overexpressing control plants. The inhibition of the induction of heat shock response correlated with impaired basal and acquired thermotolerance of the EH16-3 line. The kinetics of HSP expression suggest that the negative effect of EN-HSF1 is stronger in the early phase of the heat shock response, and that the reduction in mRNA levels is partially compensated at the translational level.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / physiology*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / physiology
  • DNA-Binding Proteins / biosynthesis
  • Gene Expression Regulation, Plant
  • Genes, Dominant
  • Genetic Vectors
  • Heat Shock Transcription Factors
  • Heat-Shock Proteins / genetics*
  • Heat-Shock Proteins / physiology
  • Heat-Shock Response*
  • Plant Proteins
  • Plants, Genetically Modified
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Repressor Proteins / genetics
  • Repressor Proteins / physiology
  • Transcription Factors / biosynthesis
  • Transcription Factors / genetics*
  • Transcription Factors / physiology


  • Arabidopsis Proteins
  • DNA-Binding Proteins
  • HSF1 protein, Arabidopsis
  • Heat Shock Transcription Factors
  • Heat-Shock Proteins
  • Plant Proteins
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • Transcription Factors