Histones/DNA Ratio in Young and Old Root Meristems ofTriticum DurumCaryopses

Cytophotometric Analyses andin VitroCulture Test in the Embryo First Node of OldTriticum DurumCaryopses

“…Since meristematic root nuclei alone in Triticum durum caryopses had a higher amount of fast-green stainable histones in aged than in young embryos (INNOCENTI and BITONTI 1979) the loss of the metabolic activity might be related, in some way, to the inactivation of the chromatin by the nuclear his tones.…”

Changes in Histones/DNA Ratio in Scutellum Nuclei During Ageing ofTriticum DurumCaryopses

“…Since during seed storage the histones/DNA ratio of meristematic tissues, which lose their metabolic activity (INNOCENTI and FLORIS 1979) appears higher than in young seeds (INNOCENTI and BITONTI 1979), it seems worthy of note that the scutellum tissues of aged non-germinating seeds show a metabolic activity similar to that of young seeds (INNOCENTI and FLORIS 1979). Besides, if we analyze the histones/DNA ratio in epithelium cells of the scutellum in young and old seeds we see that the ratio does not change At this point we might conclude that the ageing process acts in a different way not only between single embryo zones (INNOCENTI and FLORIS 1979) but even between tissues of the same organ (epithelium and parenchyma of scutellum).…”

“…The study of the localization of the last activity in the embryo of aged non-germinating seeds raises some questions regarding the nuclear changes produced in different tissues of seeds subjected to prolonged storage_ As the histones/DNA ratio changes during ageing and appears to be higher in root meristematic nuclei of old caryopses (INNOCENTI and BITONTI 1979) our purpose in the present work is to decide whether similar changes in histones/DNA ratio take place also in scutellum nuclei of aged seeds.…”