Histone acetyltransferase GCN5 is essential for heat stress-responsive gene activation and thermotolerance in Arabidopsis

Plant J. 2015 Dec;84(6):1178-91. doi: 10.1111/tpj.13076.


Exposure to temperatures exceeding the normal optimum levels, or heat stress (HS), constitutes an environmental disruption for plants, resulting in severe growth and development retardation. Here we show that loss of function of the Arabidopsis histone acetyltransferase GCN5 results in serious defects in terms of thermotolerance, and considerably impairs the transcriptional activation of HS-responsive genes. Notably, expression of several key regulators such as the HS transcription factors HSFA2 and HSFA3, Multiprotein Bridging Factor 1c (MBF1c) and UV-HYPERSENSITIVE 6 (UVH6) is down-regulated in the gcn5 mutant under HS compared with the wild-type. Chromatin immunoprecipitation (ChIP) assays indicated that GCN5 protein is enriched at the promoter regions of HSFA3 and UVH6 genes, but not in HSFA2 and MBF1c, and that GCN5 facilitates H3K9 and H3K14 acetylation, which are associated with HSFA3 and UVH6 activation under HS. Moreover, constitutive expression of UVH6 in the gcn5 mutant partially restores heat tolerance. Taken together, our data indicate that GCN5 plays a key role in the preservation of thermotolerance via versatile regulation in Arabidopsis. In addition, expression of the wheat TaGCN5 gene re-establishes heat tolerance in Arabidopsis gcn5 mutant plants, suggesting that GCN5-mediated thermotolerance may be conserved between Arabidopsis and wheat.

Keywords: Arabidopsis thaliana; GCN5; HSFA3; UVH6; heat stress; histone acetylation; wheat.

MeSH terms

  • Acetylation
  • Adaptation, Physiological / genetics
  • Adaptation, Physiological / physiology
  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Enzymologic / physiology*
  • Gene Expression Regulation, Plant / physiology*
  • Heat Shock Transcription Factors
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / metabolism
  • Histone Acetyltransferases / genetics
  • Histone Acetyltransferases / metabolism*
  • Histones / metabolism
  • Hot Temperature*
  • Mutation
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Triticum / genetics
  • Triticum / metabolism


  • Arabidopsis Proteins
  • DNA-Binding Proteins
  • HSFA2 protein, Arabidopsis
  • HSFA3 protein, Arabidopsis
  • Heat Shock Transcription Factors
  • Heat-Shock Proteins
  • Histones
  • Plant Proteins
  • Transcription Factors
  • UVH6 protein, Arabidopsis
  • GCN5 protein, Arabidopsis
  • Histone Acetyltransferases