RNA-directed DNA methylation: an epigenetic pathway of increasing complexity

Nat Rev Genet. 2014 Jun;15(6):394-408. doi: 10.1038/nrg3683. Epub 2014 May 8.


RNA-directed DNA methylation (RdDM) is the major small RNA-mediated epigenetic pathway in plants. RdDM requires a specialized transcriptional machinery that comprises two plant-specific RNA polymerases - Pol IV and Pol V - and a growing number of accessory proteins, the functions of which in the RdDM mechanism are only partially understood. Recent work has revealed variations in the canonical RdDM pathway and identified factors that recruit Pol IV and Pol V to specific target sequences. RdDM, which transcriptionally represses a subset of transposons and genes, is implicated in pathogen defence, stress responses and reproduction, as well as in interallelic and intercellular communication.

Publication types

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

MeSH terms

  • DNA Methylation / physiology*
  • DNA-Directed RNA Polymerases / genetics
  • DNA-Directed RNA Polymerases / metabolism*
  • Epigenesis, Genetic / physiology*
  • Eukaryota / physiology*
  • RNA, Small Untranslated / genetics
  • RNA, Small Untranslated / metabolism*


  • RNA, Small Untranslated
  • DNA-Directed RNA Polymerases