title: Evidence for the selective replication of dwarf pea DNA evoked by exogenous gibberellin application.
abstract: Characteristics of the total DNA preparations isolated from apical parts of dwarf pea seedlings untreated and treated with gibberellic acid (GA3) were compared. Analytical centrifugation in a self-generated CsCl density gradient revealed the occurrence of a heavy satellite DNA band (p = 1.712 g X cm-3) in addition to the main DNA band (p = 1.696 g X cm-3) in the DNA preparation extracted from GA3-treated seedlings, that could not be detected in the DNA isolated from untreated plants. The existence of this GC-rich DNA fraction was additionally confirmed by means of derivative DNA melting profiles. Comparison of the reassociation kinetics obtained for control DNA with DNA from GA3-treated plants showed changes in the percentage distribution of three main DNA sequence classes, with different repetition frequency in the haploid pea genome. It is postulated that such a variation in the percentage of different C0t families might reflect the selective DNA replication evoked by hormonal treatment of dwarf pea plants.
mesh_terms: D001483:Base Sequence; D004261:DNA Replication / Q000187:drug effects*; D007887:Fabaceae; D005875:Gibberellins / Q000494:pharmacology*; D009693:Nucleic Acid Hybridization; D010946:Plants, Medicinal
chemical_list: D005875:Gibberellins