title: Enhanced nucleolar parameters in Vicia faba L. induced by 5-azacytidine may be only partly attributed to DNA demethylation.
abstract: We aimed to find if diminishing rDNA expression in differentiating and differentiated root parenchyma, in spite of DNA endoreplication, could be related to rDNA methylation. The effect of 5-azacytidine (10(-6)M, 72 h) was studied in successive segments of Vicia faba roots. In 5-azacytidine-treated cells, nucleolar parameters: [3H] uridine incorporation, size, amount of AgNOR protein and the number of bi-nucleolate cells were increased. [3H] uridine incorporation and the amount of AgNOR protein were significantly correlated. In meristems, HPLC analysis demonstrated a decrease in m5dC content by 3.7%. Southern hybridization showed demethylation at CCGG sites in repetitive BamHI sequences and discrete demethylation in coding region of rDNA.
authors.affiliation: Department of Plant Cytology and Cytochemistry, University of Lódź, Poland.
authors.forename: M J
authors.initials: MJ
authors.lastname: Olszewska
authors.forename: T
authors.initials: T
authors.lastname: Sakowicz
authors.forename: J
authors.initials: J
authors.lastname: Kaźmierczak
authors.forename: P
authors.initials: P
authors.lastname: Luchniak
mesh_terms: D001374:Azacitidine / Q000494:pharmacology*; D015139:Blotting, Southern; D002466:Cell Nucleolus / Q000187:drug effects* / Q000235:genetics; D002851:Chromatography, High Pressure Liquid; D019175:DNA Methylation / Q000187:drug effects*; D004261:DNA Replication / Q000187:drug effects; D018744:DNA, Plant / Q000096:biosynthesis / Q000737:chemistry; D007887:Fabaceae / Q000166:cytology* / Q000187:drug effects* / Q000235:genetics; D008954:Models, Biological; D010946:Plants, Medicinal; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D018744:DNA, Plant; D001374:Azacitidine