title: RNA-directed DNA methylation: an epigenetic pathway of increasing complexity.
abstract: 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.
authors.affiliation: Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115, Taiwan.
authors.forename: Marjori A
authors.initials: MA
authors.lastname: Matzke
authors.affiliation: School of Plant Sciences, University of Arizona, Tucson, Arizona 85721-0036, USA.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Mosher
mesh_terms: D019175:DNA Methylation / Q000502:physiology*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D044127:Epigenesis, Genetic / Q000502:physiology*; D056890:Eukaryota / Q000502:physiology*; D058727:RNA, Small Untranslated / Q000235:genetics / Q000378:metabolism*
chemical_list: D058727:RNA, Small Untranslated; D012321:DNA-Directed RNA Polymerases