Low temperature induced metabolic changes in the shoot meristematic region of Marquillo × Kenya Farmer wheat dwarf 1 plants

1972 ◽  
Vol 50 (2) ◽  
pp. 285-293 ◽  
Author(s):  
J. D. Mahon ◽  
D. T. Canvin
Keyword(s):  
Inorganic Phosphate ◽  
Apical Meristem ◽  
Distribution Patterns ◽  
Organic Phosphate ◽  
Meristematic Tissue ◽  
Meristematic Region ◽  
Initial Decrease ◽  
Meristematic Activity ◽  
Cellular Destruction ◽  
Radiotracer Techniques

Marquillo × Kenya Farmer 1 (Mql × KF 1) wheat plants respond to very short 16° treatment by decreased meristematic activity of the apical meristem and extensive cellular destruction in young leaf and stem tissues. By radiotracer techniques the metabolism of 3H-thymidine, 32P, and 14C-leucine fed to intact shoot tissues of Mql × KF 1 and normal Marquillo (Mql) plants were studied.Immediately after the onset of 16° treatment, the incorporation of both 3H-thymidine and 32P into the DNA of Mql × KF 1 meristematic regions began to decline rapidly although the total uptake of label into the meristematic tissue remained constant. The incorporation of 32P into the RNA, the acid-soluble organic phosphate compounds, and phospholipids of the Mql × KF 1 meristems also declined during the first 24 h and the inorganic phosphate radioactivity increased. After the initial decrease, the proportion of radioactivity in the RNA and acid-soluble organic compounds increased to near control levels. The distribution patterns of both 3H-thymidine and 32P were unchanged in the meristematic region of Mql × KF 1 plants at 26° or Mql plants at 16° or 26°. Protein synthesis in meristematic regions, measured by the incorporation of 14C-leucine, responds to temperature similarly in Mql × KF 1 and Mql plants.The inhibitions of mitosis, phospholipid synthesis, and DNA synthesis were extremely rapid and reversible after short 16° exposures, and are thought to be close to the primary process of temperature lethality of Mql × KF 1 plants. Although it is not known if any of these processes are responsible for the others, it is proposed that the cellular destruction is caused by the inability of cells in the elongating regions to synthesize the phospholipid components of membranes.

HYDROLYSIS OF LECITHIN BY PLANT PLASTID ENZYMES

1955 ◽  
Vol 33 (1) ◽  
pp. 575-589 ◽  
Author(s):  
Morris Kates
Keyword(s):  
Phosphatidic Acid ◽  
Inorganic Phosphate ◽  
Organic Phosphate ◽  
Water Soluble ◽  
Lag Phase ◽  
Carrot Root ◽  
First Order ◽  
Spinach Chloroplasts ◽  
Egg Lecithin ◽  
Hydrolysis Of

Enzymatic liberation of choline from egg lecithin by plastid fractions from sugar beet, spinach, and cabbage leaves and from carrot root was a rapid, first order reaction (up to 70% hydrolysis), and was not preceded by a lag phase. None of the choline-containing products of lecithin degradation (lysolecithin, glycerylphosphorylcholine, or phosphorylcholine) lost choline on incubation with spinach chloroplasts. Inorganic phosphate liberation from lecithin by the plastids was preceded by a lag phase and was much slower than choline liberation. Spinach chloroplasts catalyzed the liberation of inorganic phosphate from L-α-phosphatidic acid and from L-α-glycerophosphate. The water-soluble organic phosphate liberated from lecithin by spinach chloroplasts was identified chromatographically as phosphorylcholine. The ether-soluble organic phosphate produced during the hydrolysis of egg lecithin by carrot plastids was isolated and identified as L-α-phosphatidic acid. These observations suggest that the enzymatic hydrolysis of lecithin by plant plastids involves the following reactions: (1) lecithin → L-α-phosphatidic acid + choline; (2) L-α-phosphatidic acid → inorganic phosphate + diglyceride and/or (3) L-α-phosphatidic acid → glycerophosphate + fatty acids and (4) glycerophosphate → inorganic phosphate + glycerol; and (5) lecithin → phosphorylcholine + diglyceride. The L-α-structure for egg lecithin was confirmed.

Metabolic Acidosis is a Potent Stimulus for Cellular Inorganic Phosphate Generation in Uraemia

1995 ◽  
Vol 88 (4) ◽  
pp. 405-412 ◽  
Author(s):  
Alan Bevington ◽  
Dennis Brough ◽  
Frease E. Baker ◽  
Jane Hattersley ◽  
John Walls
Keyword(s):  
Steady State ◽  
Metabolic Acidosis ◽  
Inorganic Phosphate ◽  
Lactate Production ◽  
Extracellular Fluid ◽  
Low Ph ◽  
Organic Phosphate ◽  
Glycolytic Flux ◽  
Before And After

1. During metabolic acidosis, significant fluxes of inorganic phosphate (Pi) may occur from cellular to extracellular fluid. In this study Pi was measured in erythrocytes of uraemic patients before and after haemodialysis and was related to their plasma pH (acidosis), plasma Pi (hyperphosphataemia) and cellular organic phosphate concentrations. 2. Before dialysis, the ratio of cellular to extracellular Pi concentration correlated inversely with plasma pH, increasing 2.5-fold as pH fell from 7.4 to 7.2. 3. An increase in cellular Pi similar to that seen in the patients was observed within 90 min of adding acid to normal erythrocytes in vitro. 4. The total Pi content of the cell suspension increased 25% on decreasing plasma pH from 7.4 to 7.2, largely as a result of generation of Pi from 2,3-bisphosphoglycerate in the cells. This was accompanied by net efflux of Pi into plasma. 5. In addition, the increase in the steady-state cellular Pi concentration on adding a constant extracellular Pi load was 50% greater at pH 7.2 than at 7.4, implying that alterations in the regulation of the transmembrane Pi gradient also contribute to the rise in cellular Pi observed at low pH. 6. At normal plasma Pi concentration (1 mM), glycolytic flux (lactate production) was inhibited by 20% when pH was lowered from 7.4 to 7.2. However, this inhibition was blocked when cellular Pi was increased by adding Pi to the plasma in vitro. 7. Metabolic acidosis is therefore a potent stimulus for Pi generation in erythrocytes, and this Pi may serve to stimulate glycolysis which is normally inhibited by low pH.

Low temperature effects on growth and physiology specific to a "grass-clump" dwarf wheat hybrid

1972 ◽  
Vol 50 (2) ◽  
pp. 253-261 ◽  
Author(s):  
J. D. Mahon ◽  
D. T. Canvin
Keyword(s):  
Low Temperature ◽  
Shoot Growth ◽  
Growth Habit ◽  
Temperature Response ◽  
Dry Weight ◽  
Growth Responses ◽  
Meristematic Region ◽  
Meristematic Activity ◽  
Dwarf Wheat ◽  
Induced Changes

The growth habit of "grass-clump" dwarf wheat plants can be affected by extremely short 16° treatments if given repeatedly. To localize the earliest growth responses in plants of one such hybrid (Mql × KF 1), the temperature sensitivity of plants of different ages, and the earliest temperature-induced changes in growth, development, and shoot physiology were investigated and compared with the responses of normal wheat plants.Mql × KF 1 plants growing at 26° responded to progressively shorter 16° treatments as they aged and plants exposed to 16° after 10 days growth at 26° were unable to recover from low temperature treatments of 3–5 days duration. Although shoot growth (as dry weight) of Mql × KF 1 stopped abruptly after 7 days at 16°, root growth (as dry weight) continued for at least 15 days. The rates of CO2 and water vapor exchange in individual leaves responded to low temperature similarly in both the dwarf and normal plants and did not markedly decrease until after 4 days at 16°. The most rapid low temperature response specific to Mql × KF 1 plants was cessation in primary tiller development immediately after the beginning of 16° exposure. It is proposed that the primary 16° effect is on the shoot meristematic region and that other changes in growth and physiology result from the lack of meristematic activity in the young growing region.

scholarly journals Standardised neonatal parenteral nutrition formulations – Australasian Neonatal Parenteral Nutrition Consensus update 2017

2019 ◽  
Author(s):  
Srinivas Bolisetty ◽  
David Osborn ◽  
Tim Schindler ◽  
John Sinn ◽  
Girish Deshpande ◽  
...  
Keyword(s):  
Amino Acid ◽  
Parenteral Nutrition ◽  
Nutrient Intake ◽  
Inorganic Phosphate ◽  
Cost Savings ◽  
Organic Phosphate ◽  
Lipid Emulsions ◽  
Phosphate Content ◽  
Australasian Region ◽  
Nutrition Practice

Abstract The first consensus standardised neonatal parenteral nutrition formulations were implemented in many neonatal units in Australia in 2012. The current update involving 49 units from Australia, New Zealand, Singapore, Malaysia and India was conducted between September 2015 and December 2017 with the aim to review and update the 2012 formulations and guidelines. Methods: A systematic review of available evidence for each parenteral nutrient was undertaken and new standardised formulations and guidelines were developed. Results: Five existing preterm Amino acid-Dextrose formulations have been modified and two new concentrated Amino acid-Dextrose formulations added to optimise amino acid and nutrient intake according to gestation. Organic phosphate has replaced inorganic phosphate allowing for an increase in calcium and phosphate content, and acetate reduced. Lipid emulsions are unchanged, with both SMOFlipid and ClinOleic preparations included. The physicochemical compatibility and stability of all formulations have been tested and confirmed. Guidelines to standardise the parenteral nutrition clinical practice across facilities have also been developed. Conclusions: Formulations and guidelines to standardise parenteral nutrition practice across the Australasian region have the potential to improve nutrition and clinical outcomes of neonates. Standardisation can also result in cost savings, quality improvement and error minimisation in PN prescribing and ordering.

scholarly journals The In Vitro Restoration of Red Cell 2,3-Diphosphoglycerate Levels in Banked Blood

Blood ◽  
1971 ◽  
Vol 37 (1) ◽  
pp. 52-58 ◽  
Author(s):  
FRANK A. OSKI ◽  
SUSAN F. TRAVIS ◽  
LEONARD D. MILLER ◽  
MARIA DELIVORIA-PAPADOPOULOS ◽  
ELIZABETH CANNON
Keyword(s):  
Oxygen Tension ◽  
Inorganic Phosphate ◽  
Final Concentration ◽  
Organic Phosphate ◽  
Red Cell ◽  
Fresh Blood ◽  
Stored Blood ◽  
2,3 Dpg

Abstract The demonstration that red cell levels of 2,3-DPG play a central role in determining the affinity of hemoglobin for oxygen has resulted in a renewed interest in methods for maintaining or restoring the level of this organic phosphate in stored blood. The effects of addition of inorganic phosphate, inosine and pyruvate, individually or in various combinations, all in a final concentration of 10 mM were evaluated 1 and 4 hours after supplementation of ACD-stored blood, 21 to 28 days old. In 14 studies the initial 2,3-DPG level averaged 176 mµmoles/ ml. RBC. In normal fresh blood the 2,3-DPG was 4200 ± 400 mµmoles/ml. RBC. Inosine addition raised the 2,3-DPG to 1395, inosine and phosphate to 1528, inosine and pyruvate to 3363, while the combination of inosine, pyruvate and phosphate increased the level to 6637 mµmoles/ml. RBC. After 2-3 hours of incubation most of the 2,3-DPG restoration had occured. The maximum effects did not require prior pH correction of the blood. Although inosine in a final concentration of 10 mM was required for optimum effects, the phosphate and pyruvate concentrations could be reduced to 4 mM. In the presence of inosine and phosphate alone the red cell accumulated large quantities of triose phosphates, fructose diphosphate and glucose-6-phosphate. These levels were reduced by the addition of pyruvate. Pyruvate addition appears necessary to provide sufficient NAD for maximum 2,3-DPG synthesis. Associated with 2,3-DPG restoration of the stored blood there was a rise in the P50 (the oxygen tension at which hemoglobin is 50% saturated) from a mean of 16.7 to 31.6 mm. Hg.

scholarly journals Sedimentary Organic Matter and Phosphate along the Kapuas River (West Kalimantan, Indonesia)

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Pei Sun Loh ◽  
Chen-Tung Arthur Chen ◽  
Gusti Z. Anshari ◽  
Jiann-Yuh Lou ◽  
Jough-Tai Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Sediment ◽  
Oil Palm ◽  
Inorganic Phosphate ◽  
Organic Phosphate ◽  
Sedimentary Organic Matter ◽  
Anthropogenic Sources ◽  
Loss On Ignition ◽  
West Kalimantan ◽  
Degraded Material

This study assessed the sedimentary organic matter (OM) and phosphate along the world’s longest river on an island: the Kapuas River in West Kalimantan, Indonesia. The surface sediment was tested using the loss-on-ignition experiment to determine the % labile OM, % refractory OM, and % total OM and the Rp values (the ratio of refractory to total OM). The C/N ratios and the inorganic phosphate (IP), organic phosphate (OP), and total phosphate (TP) levels were also determined. The combination of high Rp values and low C/N ratios along the upper river indicated the possible presence of relatively degraded material; the low Rp values and high C/N ratios downstream were indicative of a fresher terrestrial signal. Sedimentary P levels were the highest along the densely populated areas downstream from the Kapuas River; the second highest along the midstream river, which is surrounded by oil palm plantations; and the lowest along the upper river, which is surrounded by forest. Higher levels of OM, IP, OP, and TP downstream along the Kapuas River indicated the presence of anthropogenic sources of OM and P.

Phosphate Uptake into Organic Compounds in Skeletal Muscle

1975 ◽  
Vol 53 (2) ◽  
pp. 317-321
Author(s):  
C. R. Dunkley ◽  
J. F. Manery
Keyword(s):  
Skeletal Muscle ◽  
Organic Compounds ◽  
Adenosine Triphosphate ◽  
Inorganic Phosphate ◽  
Phosphate Uptake ◽  
Organic Phosphate ◽  
Glycerol Phosphate ◽  
Water Extracts ◽  
Ringer’S Solution ◽  
Phosphate Compounds

Isolated intact frog muscles were incubated in 32P-labelled Ringer's solution for various periods of time (30 s – 20 h). Labelled compounds were isolated from TCA, methanol–chloroform–water, and water extracts of muscle. Hexosephosphates, phosphocreatine, phosphoenolphyruvate, α-glycerol phosphate, adenosine triphosphate, and inorganic phosphate were identified after 30 s, and 4 h incubation. Much more labelling was found after 20 h. The incorporation of 32P in 30 s into organic phosphate compounds, such as α-glycerol phosphate and ATP, showed that immediate esterification of Pi occurred on, or just inside, the sarcolemma.

Compartmental analysis of phosphate in roots of intact barley seedlings

1984 ◽  
Vol 62 (5) ◽  
pp. 1076-1080 ◽  
Author(s):  
Daniel D. Lefebvre ◽  
David T. Clarkson
Keyword(s):  
Rate Constants ◽  
Inorganic Phosphate ◽  
Compartmental Analysis ◽  
Organic Phosphate ◽  
In Series

Elution profiles of 32P-labelled inorganic phosphate (Pi) from roots of intact barley plants were observed and were found to conform to the pattern theoretically derived for three compartments in series. An allowance was made for the movement of labelled phosphate from the cytoplasm into the root xylem. Transformations of labelled phosphate within metabolically labile organic pools seem to be invisible kinetically because their rate constants are generally higher than that for Pi efflux across the plasmalemma and tonoplast. It is concluded that compartmentation of phosphate between cytoplasm and vacuole can be explored usefully by this technique especially if used in conjunction with other methods which can measure the size of cytoplasmic organic phosphate pools.

scholarly journals Summer Heatwave Impacts on the European Kelp Saccharina latissima Across Its Latitudinal Distribution Gradient

2021 ◽  
Vol 8 ◽  
Author(s):  
Nora Diehl ◽  
Michael Y. Roleda ◽  
Inka Bartsch ◽  
Ulf Karsten ◽  
Kai Bischof
Keyword(s):  
Distribution Patterns ◽  
Saccharina Latissima ◽  
Latitudinal Distribution ◽  
Meristematic Tissue ◽  
Local Responses ◽  
Temperature Regimes ◽  
Intraspecific Variations ◽  
Summer Temperatures ◽  
C And N ◽  
Population Resilience

Kelps are important foundation species in coastal ecosystems currently experiencing pronounced shifts in their distribution patterns caused by ocean warming. While some populations found at species’ warm distribution edges have been recently observed to decline, expansions of some species have been recorded at their cold distribution edges. Reduced population resilience can contribute to kelp habitat loss, hence, understanding intraspecific variations in physiological responses across a species’ latitudinal distribution is crucial for its conservation. To investigate potential local responses of the broadly distributed kelp Saccharina latissima to marine heatwaves in summer, we collected sporophytes from five locations in Europe (Spitsbergen, Bodø, Bergen, Helgoland, Locmariaquer), including populations exposed to the coldest and warmest local temperature regimes. Meristematic tissue from sporophytes was subjected to increasing temperatures of Δ+2, Δ+4 and Δ+6°C above the respective mean summer temperatures (control, Δ±0°C) characteristic for each site. Survival and corresponding physiological and biochemical traits were analyzed. Vitality (optimum quantum yield, Fv/Fm) and growth were monitored over time and biochemical responses were measured at the end of the experiment. Growth was highest in northern and lowest in southern populations. Overall, northern populations from Spitsbergen, Bodø and Bergen were largely unaffected by increasing summer temperatures up to Δ+6°C. Conversely, sporophytes from Helgoland and Locmariaquer were markedly stressed at Δ+6°C: occurrence of tissue necrosis, reduced Fv/Fm, and a significantly elevated de-epoxidation state of the xanthophyll cycle (DPS). The variations in phlorotannins, mannitol and tissue C and N contents were independent of temperature treatments and latitudinal distribution pattern. Pronounced site-specific variability in response to increasing temperatures implies that exceeding a threshold above the mean summer temperature exclusively affect rear-edge (southernmost) populations.

HISTOCHEMICAL STUDIES OF ENZYME DISTRIBUTION IN SHOOT TIPS OF WHITE SPRUCE (PICEA GLAUCA (MOENCH) VOSS)

1963 ◽  
Vol 41 (10) ◽  
pp. 1509-1527 ◽  
Author(s):  
W. H. Vanden Born
Keyword(s):  
Picea Glauca ◽  
Succinic Dehydrogenase ◽  
White Spruce ◽  
Distribution Patterns ◽  
Shoot Tips ◽  
Shoot Tip ◽  
Quiescent Center ◽  
Meristematic Tissue ◽  
Stage Of Development ◽  
Enzyme Distribution

The relationship between morphological and metabolic or enzymic differentiation in shoot tips of white spruce has been investigated by histochemical methods revealing the distribution of several enzymes and other cellular constituents in tissues of the shoot tip at different times during the growing season. Most of the enzymes studied showed well-defined distribution patterns which varied with the stage of development of the shoot tip. Less seasonal variation was observed in the distribution of the other substances included.Activity of cytochrome oxidase and succinic dehydrogenase was high in the shoot apex during the flush of growth in the spring, indicating a high level of respiratory activity in that region, consistent with the rapid growth of the shoot. Peroxidase activity was associated particularly with meristematic or potentially meristematic tissue regions. The evidence substantiates the view that mitotic activity is greatest on the flanks of the apex and supports the existence of a quiescent center with relatively low activity in the apical mother cell zone, classically the origin of the primary stem tissues. High phosphatase activity was observed in the crown region and at the bases of needle and cone scale primordia.Young cones in fall or spring exhibited enzyme distribution patterns distinctly different from those in vegetative shoot tips. No evidence was obtained to indicate what enzyme or enzymes might be particularly involved in the differentiation of reproductive buds, but the results provide a basis for a further critical investigation of this differentiation by histochemical means.

Sign in / Sign up

Export Citation Format

Share Document