title: Ploidy-dependent changes in the epigenome of symbiotic cells correlate with specific patterns of gene expression.
abstract: The formation of symbiotic nodule cells inMedicago truncatulais driven by successive endoreduplication cycles and transcriptional reprogramming in different temporal waves including the activation of more than 600 cysteine-richNCRgenes expressed only in nodules. We show here that the transcriptional waves correlate with growing ploidy levels and have investigated how the epigenome changes during endoreduplication cycles. Differential DNA methylation was found in only a small subset of symbiotic nodule-specific genes, including more than half of theNCRgenes, whereas in most genes DNA methylation was unaffected by the ploidy levels and was independent of the genes' active or repressed state. On the other hand, expression of nodule-specific genes correlated with ploidy-dependent opening of the chromatin as well as, in a subset of tested genes, with reduced H3K27me3 levels combined with enhanced H3K9ac levels. Our results suggest that endoreduplication-dependent epigenetic changes contribute to transcriptional reprogramming in the differentiation of symbiotic cells.
authors.affiliation: Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, H-6726 Szeged, Hungary.|Institute for Integrative Biology of the Cell, UMR9198, CNRS, Université Paris-Sud, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, 91198 Gif-sur-Yvette, France.
authors.forename: Marianna
authors.initials: M
authors.lastname: Nagymihály
authors.affiliation: Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Alaguraj
authors.initials: A
authors.lastname: Veluchamy
authors.affiliation: Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, H-6726 Szeged, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Györgypál
authors.affiliation: Instituto de Agrobiotecnología del Litoral, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas, 3000 Santa Fe, Argentina.
authors.forename: Federico
authors.initials: F
authors.lastname: Ariel
authors.affiliation: Institute of Plant Sciences Paris-Saclay, CNRS, French National Institute for Agricultural Research, Université Paris-Sud, Université Evry, Université Paris-Diderot, Sorbonne Paris-Cité, Universite Paris-Saclay, 91405, Orsay, France.
authors.forename: Teddy
authors.initials: T
authors.lastname: Jégu
authors.affiliation: Institute of Plant Sciences Paris-Saclay, CNRS, French National Institute for Agricultural Research, Université Paris-Sud, Université Evry, Université Paris-Diderot, Sorbonne Paris-Cité, Universite Paris-Saclay, 91405, Orsay, France.
authors.forename: Moussa
authors.initials: M
authors.lastname: Benhamed
authors.affiliation: Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, H-6726 Szeged, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Szűcs
authors.affiliation: Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, H-6726 Szeged, Hungary.
authors.forename: Attila
authors.identifier: 0000-0002-4421-6554
authors.initials: A
authors.lastname: Kereszt
authors.affiliation: Institute for Integrative Biology of the Cell, UMR9198, CNRS, Université Paris-Sud, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, 91198 Gif-sur-Yvette, France; kondorosi.eva@brc.mta.hu peter.mergaert@i2bc.paris-saclay.fr.
authors.forename: Peter
authors.initials: P
authors.lastname: Mergaert
authors.affiliation: Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, H-6726 Szeged, Hungary; kondorosi.eva@brc.mta.hu peter.mergaert@i2bc.paris-saclay.fr.|Institute for Integrative Biology of the Cell, UMR9198, CNRS, Université Paris-Sud, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, 91198 Gif-sur-Yvette, France.
authors.forename: Éva
authors.initials: É
authors.lastname: Kondorosi
mesh_terms: D057890:Epigenomics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D018745:Genome, Plant; D046913:Medicago truncatula / Q000235:genetics* / Q000378:metabolism; D011003:Ploidies; D053204:Root Nodules, Plant / Q000378:metabolism; D020579:Sinorhizobium / Q000502:physiology*; D013559:Symbiosis
keywords: DNA methylation; Medicago truncatula; chromatin structure; nodule-specific cysteine-rich peptides; symbiosis