Enhanced nucleolar parameters in Vicia faba L. induced by 5-azacytidine may be only partly attributed to DNA demethylation.
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.
Olszewska
M J
MJ
Department of Plant Cytology and Cytochemistry, University of Lódź, Poland.
Sakowicz
T
T
Kaźmierczak
J
J
Luchniak
P
P
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
D018744:DNA, Plant; D001374:Azacitidine