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.

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.

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.

Nuclear proteins of quiescent and mitotically active cells in shoot meristems of Tradescantia paludosa

1974 ◽  
Vol 52 (9) ◽  
pp. 2049-2053 ◽  
Author(s):  
R. S. Tobin ◽  
Kyu-Byung Yun ◽  
J. M. Naylor
Keyword(s):  
Nuclear Proteins ◽  
Zone Of Inhibition ◽  
Interphase Nuclei ◽  
Lateral Buds ◽  
Dye Binding ◽  
Tradescantia Paludosa ◽  
Shoot Meristems

In inhibited lateral buds of Tradescantia paludosa, interphase nuclei in the apical zone of inhibition contain higher levels of arginine per unit DNA than those of mitotically active cells in interphase or prophase. Supplementary dye-binding experiments suggest that this reflects a corresponding difference between the composition of the histone complement of chromatin in the two cells populations. The possible implications of this phenomenon are discussed.

scholarly journals Lower nitrogen excretion in pig husbandry by feeding: current and future possibilities.

1989 ◽  
Vol 37 (1) ◽  
pp. 61-70 ◽  
Author(s):  
N.P. Lenis
Keyword(s):  
Protein Content ◽  
Physiological State ◽  
Growing Pigs ◽  
Nitrogen Excretion ◽  
Total Protein Content ◽  
Synthetic Amino Acids ◽  
N Utilization ◽  
Major Argument ◽  
Protein Supply

The pollution of the environment with manure nitrogen is a major argument for improving N utilization and limiting N excretion by animals. The existing legislation covering manure application in the Netherlands is briefly reviewed. In pig nutrition, the need to match more closely the protein supply to the pig's age and physiological state is highlighted - this can result in 6% less N excretion in growing pigs and up to 24% less in breeding sows. In the long term, improving the balance of dietary protein by reducing the total protein content of feeds and supplementing the diets with synthetic amino acids is suggested. Calculations show that reducing the protein content in the diets for growing pigs by 2 percentage units would reduce N excretion by about 25%. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals 760 PB 184 INDOLE-3-ACETIC ACID REGULATES APICAL DOMINANCE BY CONTROLLING THE STATE OF WATER AND MEMBRANE LIPID COMPOSITION IN BUDS OF MALUS DOMESTICA BORKH

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 541h-542
Author(s):  
Shiow Y. Wang ◽  
Miklos Faust ◽  
Michael J. Line
Keyword(s):  
Acetic Acid ◽  
Lipid Composition ◽  
Apical Dominance ◽  
Membrane Lipid ◽  
Proton Density ◽  
Membrane Lipid Composition ◽  
Lateral Buds ◽  
Terminal Bud ◽  
Lateral Bud ◽  
Indole 3 Acetic Acid

The effect of Indole-3-acetic acid (IAA) on apical dominance in apple (Malus domestica Borkh.) buds was examined by studying changes In proton density (free water) and membrane lipid composition in lateral buds. Decapitation induced budbreak and enhanced lateral bud growth. IAA replaced apical control of lateral bud paradormancy. Maximal inhibition was obtained when IAA was applied immediately after the apical bud was removed. Delaying this application weakens the effect of IAA. An increase in proton density in lateral buds was observable 2 days after decapitation, whereas the change in membrane lipid composition occurred 4 days later. Decapitating the terminal bud induced an increase in membrane galacto- and phospholipids. and the ratio of unsaturated to corresponding saturated fatty acids. Decapitation also induced a decrease in the ratio of free sterols to phospholipids in lateral buds. Application of IAA to the terminal end of decapitated shoots inhibited the increase of proton density and prevented changes in the membrane lipid composition of lateral buds.

Estimation of Unbalanced Bacterial Growth in Inhibitory Environments by Physiological Assessment

1988 ◽  
Vol 20 (11-12) ◽  
pp. 53-59
Author(s):  
Tetsuji Chohji
Keyword(s):  
Bacterial Growth ◽  
Deoxyribonucleic Acid ◽  
Environmental Temperature ◽  
Ethanol Concentration ◽  
Physiological State ◽  
Environmental Water ◽  
Simple Relation ◽  
Unbalanced Growth ◽  
Temperature Changes ◽  
Physiological Assessment

The kinetic response of bacterial growth to an inhibitor concentration and/or environmental temperature changes was investigated. Microorganisms have a physiological state which adapts to a given environment, and they need a process to transfer to a new physiological state when the environmental condition changes. As an index of the physiological state, the cellular mass at the time of the initiation of the deoxyribonucleic acid (DNA) replication was chosen. From this viewpoint, a simple relation between the unbalanced growth behavior and the physiological state is proposed as being able to describe unbalanced growth under inhibitory and temperature changes. Applying this relation and using ethanol as an inhibitor, the calculated values of unbalanced growth after changes of ethanol concentration and/or temperature could simulate the experimental data with high accuracy. This method might also be applicable for forecasting profiles of unbalanced growth in environmental water or wastewater, which contains complex or unknown materials.

scholarly journals Apical Dominance in Apple (Malus domestica Borkh): The Possible Role of Indole-3-Acetic Acid (IAA)

1994 ◽  
Vol 119 (6) ◽  
pp. 1215-1221 ◽  
Author(s):  
Shiow Y. Wang ◽  
Miklos Faust ◽  
Michael J. Line
Keyword(s):  
Lipid Composition ◽  
Apical Dominance ◽  
Saturated Fatty Acids ◽  
Membrane Lipid ◽  
Proton Density ◽  
Membrane Lipid Composition ◽  
Lateral Buds ◽  
Terminal Bud ◽  
Lateral Bud ◽  
Bud Growth

The effect of IAA on apical dominance in apple buds was examined in relation to changes in proton density (free water) and membrane lipid composition in lateral buds. Decapitation induced budbreak and enhanced lateral bud growth. IAA replaced apical control of lateral buds and maintained paradormancy. Maximal inhibition was obtained when IAA was applied immediately after the apical bud was removed; delaying application reduced the effect of IAA. An increase in proton density in lateral buds was observed 2 days after decapitation, whereas the change in membrane lipid composition occurred 4 days later. Removing the terminal bud increased membrane galacto- and phospholipids and the ratio of unsaturated to corresponding saturated fatty acids. Decapitation also decreased the ratio of free sterols to phospholipids in lateral buds. Applying thidiazuron to lateral buds of decapitated shoots enhanced these effects, whereas applying IAA to the terminal end of decapitated shoots inhibited the increase of proton density and prevented changes in membrane lipid composition in lateral buds. These results suggest that change in water movement alters membrane lipid composition and then induces lateral bud growth. IAA, presumably produced by the terminal bud, restricts the movement of water to lateral buds and inhibits their growth in apple.

scholarly journals AUTOMATED ANALYSIS OF DEOXYRIBONUCLEIC ACID, PROTEIN AND NUCLEAR TO CYTOPLASMIC RELATIONSHIPS IN TUMOR CELLS AND GYNECOLOGIC SPECIMENS

1974 ◽  
Vol 22 (7) ◽  
pp. 616-621 ◽  
Author(s):  
J. A. STEINKAMP ◽  
H. A. CRISSMAN
Keyword(s):  
Tumor Cells ◽  
Optical Sensors ◽  
Deoxyribonucleic Acid ◽  
Pulse Height ◽  
Argon Laser ◽  
Total Protein Content ◽  
Fluorescence Signal ◽  
Green Fluorescence ◽  
Time Duration ◽  
Acid Protein

Quantitative two-color fluorescence staining techniques, coupled with flow system multiparameter cell analysis and sorting instrumentation, have been used for rapid, simultaneous determination of deoxyribonucleic acid, protein, nuclear (N) and cytoplasmic (C) diameters and N:C ratios in mammalian tumor cells and human gynecologic specimens. Cells stained in suspension for deoxyribonucleic acid and total protein content, respectively, with propidium iodide (red fluorescence) and fluorescein isothiocyanate (green fluorescence), enter a flow chamber and intersect an argon laser beam which excites cellular fluorescence. Optical sensors measure both red and green fluorescence plus the time duration of each fluorescence signal which is proportional to nuclear and cytoplasmic diameters, respectively. The resulting signals are processed and displayed as frequency distribution histograms using a multichannel pulse height analyzer. Cells are also sorted based on N:C ratios. Illustrative examples of preliminary two-color fluorescence analysis and sorting of mouse squamous tumor cells and human exfoliative vaginal cells are presented.

Sign in / Sign up

Export Citation Format

Share Document