title: DNA methylation dynamics and MET1a-like gene expression changes during stress-induced pollen reprogramming to embryogenesis.
abstract: Stress-induced plant cell reprogramming involves changes in global genome organization, being the epigenetic modifications key factors in the regulation of genome flexibility. DNA methylation, accomplished by DNA methyltransferases, constitutes a prominent epigenetic modification of the chromatin fibre which is locked in a transcriptionally inactive conformation. Changes in DNA methylation accompany the reorganization of the nuclear architecture during plant cell differentiation and proliferation. After a stress treatment, in vitro-cultured microspores are reprogrammed and change their gametophytic developmental pathway towards embryogenesis, the process constituting a useful system of reprogramming in isolated cells for applied and basic research. Gene expression driven by developmental and stress cues often depends on DNA methylation; however, global DNA methylation and genome-wide expression patterns relationship is still poorly understood. In this work, the dynamics of DNA methylation patterns in relation to nuclear architecture and the expression of BnMET1a-like DNA methyltransferase genes have been analysed during pollen development and pollen reprogramming to embryogenesis in Brassica napus L. by a multidisciplinary approach. Results showed an epigenetic reprogramming after microspore embryogenesis induction which involved a decrease of global DNA methylation and its nuclear redistribution with the change of developmental programme and the activation of cell proliferation, while DNA methylation increases with pollen and embryo differentiation in a cell-type-specific manner. Changes in the presence, abundance, and distribution of BnMET1a-like transcripts highly correlated with variations in DNA methylation. Mature zygotic and pollen embryos presented analogous patterns of DNA methylation and MET1a-like expression, providing new evidence of the similarities between both developmental embryogenic programmes.
authors.affiliation: Plant Development and Nuclear Architecture lab. Biological Research Center, CIB-CSIC, Madrid,  Spain.
authors.forename: María-Teresa
authors.initials: MT
authors.lastname: Solís
authors.forename: María
authors.initials: M
authors.lastname: Rodríguez-Serrano
authors.forename: Mónica
authors.initials: M
authors.lastname: Meijón
authors.forename: María-Jesús
authors.initials: MJ
authors.lastname: Cañal
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cifuentes
authors.forename: María C
authors.initials: MC
authors.lastname: Risueño
authors.forename: Pilar S
authors.initials: PS
authors.lastname: Testillano
mesh_terms: D029688:Brassica napus / Q000196:embryology / Q000235:genetics* / Q000254:growth & development; D002467:Cell Nucleus / Q000235:genetics; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics* / Q000378:metabolism; D019175:DNA Methylation; D019075:Electrophoresis, Capillary; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D011058:Pollen / Q000196:embryology / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological
chemical_list: D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases