CONTROL OF NUCLEAR PROCESSES BY AUXIN IN AXILLARY BUDS OF TRADESCANTIA PALUDOSA

1958 ◽  
Vol 36 (2) ◽  
pp. 221-232 ◽  
Author(s):  
J. M. Naylor
Keyword(s):  
Dna Synthesis ◽  
Mitotic Rate ◽  
Axillary Buds ◽  
Naphthalene Acetic Acid ◽  
Terminal Bud ◽  
Lateral Bud ◽  
Regulatory Effects ◽  
Inhibition Of Dna Synthesis ◽  
Nuclear Processes ◽  
Tradescantia Paludosa

Regulatory effects of auxin on mitosis and DNA synthesis were studied in lateral bud apices of Tradescnntia paludosa. In axillary buds inhibited by the terminal bud, mitoses were absent in a group of cells constituting the initials of tunica and corpus within the apex. The DNA (Feulgen) content of inter-phasic nuclei in this "zone of inhibition" was uniform and no greater than that characteristic of diploid telophase (2C), despite differences in nuclear volume. In subapical bud tissues, mitoses occurred at a low rate. Upon removal of the vegetative shoot tip, this mitotic rate was increased and the previously inhibited nuclei within the apes underwent DNA doubling to 4C, then entered prophase. These results indicate that the interphase synthesis of at least one chromosomal substance (DNA) is under auxin control. Evidence is presented that mitosis is not directly inhibited by this hormone. Naphthalene acetic acid was found to substitute for natural auxin in the inhibition of DNA synthesis.

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

1968 ◽  
Vol 46 (3) ◽  
pp. 289-298 ◽  
Author(s):  
R. S. Dwivedi ◽  
J. M. Naylor
Keyword(s):  
Deoxyribonucleic Acid ◽  
Physiological State ◽  
Total Protein Content ◽  
Zone Of Inhibition ◽  
Terminal Bud ◽  
Interphase Cells ◽  
Standard Level ◽  
Lateral Bud ◽  
Standard Value ◽  
Tradescantia Paludosa

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.

scholarly journals Inhibition of DNA synthesis in living cells by microinjection of Gi2 antibodies.

1992 ◽  
Vol 267 (2) ◽  
pp. 691-694 ◽  
Author(s):  
V J LaMorte ◽  
P K Goldsmith ◽  
A M Spiegel ◽  
J L Meinkoth ◽  
J R Feramisco
Keyword(s):  
Dna Synthesis ◽  
Living Cells ◽  
Inhibition Of Dna Synthesis

Regulation of cell reproduction in bud meristems of Tradescantia paludosa

1973 ◽  
Vol 51 (6) ◽  
pp. 1137-1145 ◽  
Author(s):  
Kyu-Byung Yun ◽  
J. M. Naylor
Keyword(s):  
Apical Dominance ◽  
Mitotic Cycle ◽  
Plant Cells ◽  
Central Zone ◽  
Apparent Absence ◽  
Cell Reproduction ◽  
Terminal Bud ◽  
Terminal Buds ◽  
Regulation Of Growth ◽  
Tradescantia Paludosa

The mitotic cycle can be arrested in the apical summit of vegetative terminal buds of Tradescantia paludosa by restricting the level of nitrogen or light available to the plant. Cells in this portion of the bud are much more sensitive to these stress conditions than those in the subjacent portion of the meristem. This differential response induced the establishment of a quiescent "central zone" which is distinguished from the rest of the meristem by the apparent absence of mitosis and DNA synthesis, larger nuclear volume, and a lower histone content of chromatin. These features are identical with those imposed by apical dominance in apices of inhibited lateral buds.The results support the view that competition for nutrients is an important causal factor in apical dominance. They suggest also that competition for nutrients within the terminal bud meristem is important in the regulation of growth in vegetative shoots in respones to conditions of the environment.

The effect of ara-C-induced inhibition of DNA synthesis on its cellular pharmacology

1990 ◽  
Vol 25 (6) ◽  
pp. 418-424 ◽  
Author(s):  
Li-Ming Wang ◽  
J. Courtland White ◽  
Robert L. Capizzi
Keyword(s):  
Dna Synthesis ◽  
Cellular Pharmacology ◽  
Inhibition Of Dna Synthesis
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