Influence of apical dominance on the nuclear proteins in cells of the lateral bud meristem in Tradescantia paludosa

Abstract

In inhibited axillary buds of Tradescantia paludosa deoxyribonucleic acid, (DNA) synthesis is blocked at the 2C (GI) level in a group of cells which constitute a "zone of inhibition" in the bud apex. The apparent DNA/histone ratio of chromatin in these interphase cells is substantially higher than the "standard" value found in nuclei of the active terminal bud. The DNA/histone ratio of chromatin in the apex of the axillary bud declines to the standard level when the cells undergo changes leading to mitosis, after the release of inhibition. In contrast to the histone level, the total protein content of chromatin in the zone of inhibition is not influenced by the change in physiological state of the bud. The significance of this shift in the histone content of chromatin is discussed.