The RdDM pathway is required for basal heat tolerance in Arabidopsis

Mol Plant. 2013 Mar;6(2):396-410. doi: 10.1093/mp/sst023. Epub 2013 Feb 1.


Heat stress affects epigenetic gene silencing in Arabidopsis. To test for a mechanistic involvement of epigenetic regulation in heat-stress responses, we analyzed the heat tolerance of mutants defective in DNA methylation, histone modifications, chromatin-remodeling, or siRNA-based silencing pathways. Plants deficient in NRPD2, the common second-largest subunit of RNA polymerases IV and V, and in the Rpd3-type histone deacetylase HDA6 were hypersensitive to heat exposure. Microarray analysis demonstrated that NRPD2 and HDA6 have independent roles in transcriptional reprogramming in response to temperature stress. The misexpression of protein-coding genes in nrpd2 mutants recovering from heat correlated with defective epigenetic regulation of adjacent transposon remnants which involved the loss of control of heat-stress-induced read-through transcription. We provide evidence that the transcriptional response to temperature stress, at least partially, relies on the integrity of the RNA-dependent DNA methylation pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / enzymology
  • Arabidopsis / genetics*
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • DNA Methylation / genetics*
  • DNA Transposable Elements / genetics
  • DNA-Directed RNA Polymerases / genetics
  • DNA-Directed RNA Polymerases / metabolism
  • Epigenesis, Genetic
  • Histone Deacetylases / genetics
  • Histone Deacetylases / metabolism
  • Hot Temperature*
  • Mutation
  • Plant Proteins / genetics
  • RNA, Plant / genetics*
  • Up-Regulation


  • Arabidopsis Proteins
  • DNA Transposable Elements
  • Plant Proteins
  • RNA, Plant
  • RNA polymerase IV, Arabidopsis
  • DNA-Directed RNA Polymerases
  • HDA6 protein, Arabidopsis
  • Histone Deacetylases