title: The arabidopsis DNA polymerase δ has a role in the deposition of transcriptionally active epigenetic marks, development and flowering.
abstract: DNA replication is a key process in living organisms. DNA polymerase α (Polα) initiates strand synthesis, which is performed by Polε and Polδ in leading and lagging strands, respectively. Whereas loss of DNA polymerase activity is incompatible with life, viable mutants of Polα and Polε were isolated, allowing the identification of their functions beyond DNA replication. In contrast, no viable mutants in the Polδ polymerase-domain were reported in multicellular organisms. Here we identify such a mutant which is also thermosensitive. Mutant plants were unable to complete development at 28°C, looked normal at 18°C, but displayed increased expression of DNA replication-stress marker genes, homologous recombination and lysine 4 histone 3 trimethylation at the SEPALLATA3 (SEP3) locus at 24°C, which correlated with ectopic expression of SEP3. Surprisingly, high expression of SEP3 in vascular tissue promoted FLOWERING LOCUS T (FT) expression, forming a positive feedback loop with SEP3 and leading to early flowering and curly leaves phenotypes. These results strongly suggest that the DNA polymerase δ is required for the proper establishment of transcriptionally active epigenetic marks and that its failure might affect development by affecting the epigenetic control of master genes.
authors.affiliation: Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina.
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Iglesias
authors.affiliation: Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina.
authors.forename: Natalia A
authors.initials: NA
authors.lastname: Bruera
authors.affiliation: Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Dergan-Dylon
authors.affiliation: Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina.
authors.forename: Cristina
authors.initials: C
authors.lastname: Marino-Buslje
authors.affiliation: J. Craig Venter Institute, Rockville, Maryland, United States of America.
authors.forename: Hernán
authors.initials: H
authors.lastname: Lorenzi
authors.affiliation: Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina; Max Planck Institute for Plant Breeding Research, Cologne, Germany.
authors.forename: Julieta L
authors.initials: JL
authors.lastname: Mateos
authors.affiliation: Max Planck Institute for Plant Breeding Research, Cologne, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Turck
authors.affiliation: Max Planck Institute for Plant Breeding Research, Cologne, Germany.
authors.forename: George
authors.initials: G
authors.lastname: Coupland
authors.affiliation: Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina; Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Pablo D
authors.initials: PD
authors.lastname: Cerdán
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000096:biosynthesis; D004258:DNA Polymerase III / Q000235:genetics*; D004261:DNA Replication / Q000235:genetics*; D044127:Epigenesis, Genetic; D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D006657:Histones / Q000235:genetics; D018398:Homeodomain Proteins / Q000096:biosynthesis; D026161:MADS Domain Proteins; D018515:Plant Leaves / Q000235:genetics; D014157:Transcription Factors / Q000096:biosynthesis
chemical_list: D029681:Arabidopsis Proteins; C418905:FT protein, Arabidopsis; D006657:Histones; D018398:Homeodomain Proteins; D026161:MADS Domain Proteins; C121158:SEP3 protein, Arabidopsis; D014157:Transcription Factors; D004258:DNA Polymerase III