scholarly journals The Physiology of Sugar-Cane IV. Effects of Inhibitors on Sugar Accumulation in Storage Tissue Slices

1960 ◽  
Vol 13 (3) ◽  
pp. 221 ◽  
Author(s):  
RL Bieleski
Keyword(s):  
Sugar Cane ◽  
Metabolic Inhibitors ◽  
Magnesium Ion ◽  
Sugar Accumulation ◽  
Tissue Slices ◽  
Storage Tissue ◽  
Cupric Ion ◽  
Mercuric Ion ◽  
Rate Of Accumulation

Various metabolic inhibitors, at pH 5� 5, affected sugar accumulation in immature sugar-cane storage tissues. The rate of accumulation was reduced by lO-5M mercuric ion, lO-<M p-chloromercuribenzoate, cyanide, and cupric ion, and 2 X lO-3M phloridzin. Accumulation was completely inhibited and sugar leakage induced by lO-5M dinitrophenol, lO-<M mercuric ion, and 10-3M p-chloromercuribenzoate, cyanide, cupric ion, azide, arsenate, and iodoacetate. The effects of 10-5M dinitrophenol and 10-4M cyanide were reversible, but that of 10-3M cyanide was irreversible. Only slight effects were produced by borate, phosphate, and magnesium ion.

scholarly journals Physiology of Sugarcane Under Water Stress: Invertase, ATP-ase and Amylase Behavior in Plants Experiencing Water Deficiency, Night Flooding and Continuous Flooding

1969 ◽  
Vol 56 (2) ◽  
pp. 115-133
Author(s):  
Alex G. Alexander ◽  
George Samuels ◽  
Gene L. Spain ◽  
Rafael Montalvo-Zapata
Keyword(s):  
Water Stress ◽  
Water Regime ◽  
Enzyme Level ◽  
Hydrolytic Enzyme ◽  
Sand Culture ◽  
Sugar Accumulation ◽  
Storage Tissue ◽  
Water Regimes ◽  
Continuous Flooding ◽  
Normal Water

Effects of water stress on growth, sugar production and enzymology of sugarcane were evaluated in two greenhouse experiments in which sugarcane of the variety P.R. 980 was grown in sand culture with controlled nutrient supply. At 14 weeks of age, four water regimes were created for each of the two experiments: No water, normal water (2 liters daily), normal water plus night flooding, and continuous flooding. One experiment was pretreated with a 0.01-percent solution of active gibberellic acid (GA) 10 days before water variables were initiated. Samples of leaf, leaf sheath, immature storage tissue and stalk tissue were harvested at 0, 2, 5, and 9 days. Enzyme assays were conducted with leaf and immature storage tissue preparations for acid invertase, adenosine triphosphatase (ATP-ase), and ß-amylase. The following results were obtained: 1. Foliar symptoms appeared between the fifth and ninth day among the low-water and continuous flooding regimes. Wilting of leaves and leaf sheaths, yellowing of leaf tips, extensive yellowing of older leaves and leaf sheaths, and severe curling of spindle tissues was general among both treatments. Symptoms were delayed but not prevented by GA pretreatment. Normal water and night flooding produced no visible effects. Whorls of adventitious roots grew from submerged nodes of continuously flooded plants. 2. Sheath moisture values ultimately declined in water-deficient and water-toxic plants regardless of GA treatment. Continuously flooded plants increased total fresh weight, regardless of leaf and sheath desiccation, when pretreated with GA. A GA role in promoting water uptake is suggested. 3. Leaf sucrose declined in water-deficient and continuously flooded sugarcane but increased in immature storage tissues. This was taken as evidence of continued sucrose transport under moisture conditions restrictive against sugar synthesis. Polarization values for milled juice indicated that GA pretreatment caused a decline of storage sucrose under a normal water regime, but GA prevented storage sucrose losses under a regime of continuous flooding. The former GA effect is interpreted in terms of growth stimulation, the latter in terms of GA involvement in sugar accumulation processes effective in transport of sucrose to storage areas. 4. Invertase was suppressed both by deficient and excessive water regimes and by GA pretreatment. Night flooding produced little effect. 5. ATP-ase was strongly suppressed by night flooding but no consistent effects were produced by the other water regimes. The ATP-ase suppression by excessive night water was interpreted as a perturbation of normal diurnal-nocturnal rhythms rather than a sensitivity of synthesis mechanisms to flooding per se. GA pretreatment suppressed ATP-ase among all water regimes. Assuming that foliar ATP-ase is a functional entity of photosynthetic phosphorylation, the GA effect was taken as further evidence of a GA influence upon sugarcane photosynthesis. 6. Foliar amylase remained at a constant level in water-deficient cane, while other water regimes tended to increase the enzyme. Amylase was less sensitive to water regime than invertase and appeared to be synthesized under flood conditions highly repressive for invertase. It is concluded that low- and high-water regimes tend to produce common effects upon the overall synthesis and utilization of sugar in the cane plant. Hormone level may affect the rate of sugar utilization within high and low water regimes without altering the outward manifestations of these regimes. Hydrolytic enzyme level is apparently affected indirectly by prolonged water stress or by perturbation of endogenous day-night rhythms. However, the enzymes measured were not sufficiently sensitive to changing water supply to serve as indicators of water status.

scholarly journals The Physiology of Sugar-Cane III. Characteristics of Sugar Uptake in Slices of Mature and Immature Storage Tissue

1960 ◽  
Vol 13 (3) ◽  
pp. 203 ◽  
Author(s):  
RL Bieleski
Keyword(s):  
Sugar Cane ◽  
Free Space ◽  
Sugar Concentration ◽  
Sugar Uptake ◽  
Accumulation Process ◽  
Anaerobic Conditions ◽  
Storage Tissue ◽  
Constant Rate ◽  
Two Stages ◽  
Initial Uptake

Sugar uptake by slices of sugar-cane storage tissue took place in two stages. The initial uptake reached an equilibrium within 1 hr, the level being proportional to the external sugar concentration, independent of the sugar, and unaffected by anaerobic conditions. This sugar diffused out rapidly when the tissue was placed in water. It was thus contained in the apparent free space, 10-20 per cent. of the tissue volume. The secondary uptake continued up to 60 hr at a slow, constant rate, 1-5 mgjgjday, independent of sugar concentration above 2� 0 per cent., dependent on the sugar, and inhibited by anaerobic conditions. This sugar did not diffuse out when the tissue was placed in water. It was concluded that the secondary uptake was an active accumulation process.

scholarly journals Maintenanance of Viability of Carrot Tissue Slices in Washing Solutions After Cutting

1971 ◽  
Vol 24 (2) ◽  
pp. 397 ◽  
Author(s):  
RA Wildes ◽  
TF Neales
Keyword(s):  
Biological Activity ◽  
Boric Acid ◽  
Calcium Chloride ◽  
Respiration Rate ◽  
Bacterial Contamination ◽  
Plant Tissues ◽  
Tissue Slices ◽  
Storage Tissue ◽  
Physiological Studies

In studies of the characteristics of the uptake of boric acid by plant tissues (Wildes and Neales, unpublished data) we used disks cut from carrot roots. Bacon, MacDonald, and Knight (1965) have emphasized the necessity of using storage tissue free of bacteria for such physiological studies. In the course of our experiments we therefore investigated the extent of bacterial contamination in carrot disks immediately after cutting, and also examined the effects of chloramphenicol and calcium chloride in the washing solution on the extent of the development of bacterial contamination in the disks. We also made measurements of various properties that gave evidence of their normal biological activity. The loss of this activity, in our experience, was characterized by a final loss of turgor, browning of both tissue and washing solutions, and a failure to respond in respiration rate to both the addition of salts and 2,4-dinitrophenol.

scholarly journals Sugar Accumulation Cycle in Sugar Cane. III. Physical & Metabolic Aspects of Cycle in Immature Storage Tissues

1963 ◽  
Vol 38 (3) ◽  
pp. 348-354 ◽  
Author(s):  
J. A. Sacher ◽  
M. D. Hatch ◽  
K. T. Glasziou
Keyword(s):  
Sugar Cane ◽  
Sugar Accumulation

AEROBIC GLYCOLYSIS OF X-IRRADIATED THYMOCYTES

1963 ◽  
Vol 41 (1) ◽  
pp. 2157-2169 ◽  
Author(s):  
Kimiko Araki ◽  
D. K. Myers
Keyword(s):  
Lactic Acid ◽  
Cell Damage ◽  
Aerobic Glycolysis ◽  
Lactate Production ◽  
Metabolic Inhibitors ◽  
Anaerobic Glycolysis ◽  
Acid Accumulation ◽  
X Irradiation ◽  
Thymus Cells ◽  
Rate Of Accumulation

The aerobic lactate production of rat thymocyte suspensions incubated at 37 °C for 2 hours was doubled following exposure to approximately 70 r X-radiation. Lower doses down to 18 r also produced a significant increase in aerobic lactate production. Increased lactate accumulation following exposure to 1000 r was observed after incubation for as little as 30–60 minutes, though the rate of accumulation increased still further between 2 and 4 hours incubation. A decrease in pH or temperature during incubation of irradiated thymocyte suspensions minimized the lactic acid accumulation. A comparison of the effects of X-irradiation in different media and of the effects of several metabolic inhibitors suggested that the increase in aerobic lactate production was a sensitive indicator of cell damage associated with the loss of intracellular potassium ions.Respiration and anaerobic glycolysis of the thymus cells were both much less sensitive than aerobic glycolysis to the effects of X-irradiation. The "anaerobic" lactate production of rat thymocyte suspensions in the presence of dinitrophenol was reduced by 50% after exposure to 5000–6000 r of X-radiation.

Sign in / Sign up

Export Citation Format

Share Document