title: A two-step process for epigenetic inheritance in Arabidopsis.
abstract: In Arabidopsis, multisubunit RNA polymerases IV and V orchestrate RNA-directed DNA methylation (RdDM) and transcriptional silencing, but what identifies the loci to be silenced is unclear. We show that heritable silent locus identity at a specific subset of RdDM targets requires HISTONE DEACETYLASE 6 (HDA6) acting upstream of Pol IV recruitment and siRNA biogenesis. At these loci, epigenetic memory conferring silent locus identity is erased in hda6 mutants such that restoration of HDA6 activity cannot restore siRNA biogenesis or silencing. Silent locus identity is similarly lost in mutants for the cytosine maintenance methyltransferase, MET1. By contrast, pol IV or pol V mutants disrupt silencing without erasing silent locus identity, allowing restoration of Pol IV or Pol V function to restore silencing. Collectively, these observations indicate that silent locus specification and silencing are separable steps that together account for epigenetic inheritance of the silenced state.
authors.affiliation: Howard Hughes Medical Institute, Indiana University, Bloomington, IN 47405, USA; Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Blevins
authors.affiliation: Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Pontvianne
authors.affiliation: Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Ross
authors.initials: R
authors.lastname: Cocklin
authors.affiliation: Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN 47405, USA; School of Informatics and Computing, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Ram
authors.initials: R
authors.lastname: Podicheti
authors.affiliation: Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Chinmayi
authors.initials: C
authors.lastname: Chandrasekhara
authors.affiliation: School of Informatics and Computing, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Satwica
authors.initials: S
authors.lastname: Yerneni
authors.affiliation: School of Informatics and Computing, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Braun
authors.affiliation: Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA.
authors.forename: Brandon
authors.initials: B
authors.lastname: Lee
authors.affiliation: Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Doug
authors.initials: D
authors.lastname: Rusch
authors.affiliation: Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA; Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Keithanne
authors.initials: K
authors.lastname: Mockaitis
authors.affiliation: Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN 47405, USA; School of Informatics and Computing, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Haixu
authors.initials: H
authors.lastname: Tang
authors.affiliation: Howard Hughes Medical Institute, Indiana University, Bloomington, IN 47405, USA; Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA. Electronic address: cpikaard@indiana.edu.
authors.forename: Craig S
authors.initials: CS
authors.lastname: Pikaard
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D003596:Cytosine / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D004251:DNA Transposable Elements; D012321:DNA-Directed RNA Polymerases / Q000235:genetics* / Q000378:metabolism; D044127:Epigenesis, Genetic; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D056426:Genetic Loci; D005838:Genotype; D040941:Heredity; D006655:Histone Deacetylases / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000096:biosynthesis
chemical_list: D029681:Arabidopsis Proteins; D004251:DNA Transposable Elements; D034741:RNA, Small Interfering; D003596:Cytosine; C499608:MET1 protein, Arabidopsis; D004248:DNA (Cytosine-5-)-Methyltransferases; C499181:RNA polymerase IV, Arabidopsis; C538841:RNA polymerase V, Arabidopsis; D012321:DNA-Directed RNA Polymerases; C432452:AT5G63110 protein, Arabidopsis; D006655:Histone Deacetylases