[76] Colorimetric procedures for amino acids

Spies, Joseph R.

doi:10.1016/s0076-6879(57)03417-5

Cited by 352 publications

(177 citation statements)

References 12 publications

Supporting

Mentioning

173

Contrasting

Unclassified

Order By: Relevance

“…Total soluble amino acids and total soluble sugar contents in root exudates were measured by standard procedures using ninhydrin (Spies, 1957) and sulphonated a-napthol (Denvor, 1950) reagents, respectively. The concentrations of amino acids and sugars were expressed as milligram equivalents of leucine or glucose, per gram dry wt of root.…”

Section: Light Intensity-p Interactionmentioning

confidence: 99%

Interaction of Light Intensity and Soil Temperature With Phosphorus Inhibition of Vesicular‐arbuscular Mycorrhiza Formation

Leonard²,

1982

View full text Add to dashboard Cite

SUMMARYThe interaction between light intensity and soil temperature with phosphorus inhibition of vesicular-arbuscular mycorrhiza (VAM) formation in sudangrass (Sorghum vulgare, Pers.) was investigated in P-deficient (0-5 mg P kg~^) sandy soil amended with 0 (OP), 15 (15P) and 30 (30P) mg P kg"' soil as superphosphate. For seedlings inoculated with Glomus fasciculatus and grown at 100, 75, and 50"0 of glasshouse light intensity, the reduction in VAM formation by added soil P (15 P and 30P) was greatest at the lower light levels, whereas in the OP treatment, VAM fornaation was unaffected by a decrease in light intensity. Increases in root P concentration resulted from both soil P amendment and, in the 15P treatment, from a decrease in light intensity, and were associated with decreases in root membrane permeability and corresponding decreases in root exudation of amino acids and sugars. The reduction in sugar exudation in the 15P treatment at lower light intensity was paralleled by a decrease in root extract levels of sugars, but decreases in amino acid exudation could not be explained by changes in amino acid levels in root extracts. These results suggest that P inhibition of VAM formation is more severe at lower light intensities because of a decrease in membrane-mediated exudation, although a reduction in sugar levels in root cells may also contribute to tbe observed decrease in exudation.When inoculated seedlings were grown at 25, 30, and 35°C soil temperatures, the reduction in VAM formation in the 1 5P and 30P treatments was overcome by increase in soil temperature. The increase in VAM formation by increased temperature in the 15P plants was associated with significant increases in root membrane permeability and exudation without a corresponding change in root P concentration. In the OP treatment, an increase in soil temperature increased VAM formation with little effect on root exudation, which suggested an effect of temperature on Glomus fasciculatus. Higher soil temperature may increase VAM formation through either a direct effect of temperature on tbe fungus or an indirect effect via an increase in leakage of root metabolites necessary for fungal activity, or both.

show abstract

Section: Light Intensity-p Interactionmentioning

confidence: 99%

Interaction of Light Intensity and Soil Temperature With Phosphorus Inhibition of Vesicular‐arbuscular Mycorrhiza Formation

Leonard²,

1982

View full text Add to dashboard Cite

show abstract

“…The centrifuged solutions were heated, and trichloroacetic acid was added to pronase solutions to precipitate protein. Glucanase activity was measured in test solutions with the hexokinase test, chitinase by the release of N-acetylglucosamine (Kumar & Hansen, 1972), and pronase by measuring the release of amino acid within ninhydrin (Spies, 1957). All enzyme solutions were examined by electron microscopy to determine what structure, if any, was contributed by the enzymes themselves to the treated wall material.…”

Section: N T K O D U C R L O Nmentioning

confidence: 99%

Chemistry and Architecture of the Mycelial Wall of Agaricus bisporus

Michalenko

Hohl

Rast

1976

Journal of General Microbiology

View full text Add to dashboard Cite

A purified wall fraction was prepared from the mycelium of Agaricus bisporus. The isolated wall consisted of 43",, (wiw) chitin, 1 4 "~) KOH-soluble glucan, 27Oh /I-glucan, 1 6 O , protein and ~-5~) , , lipid. Traces of mannose and xylose were detected by gas chromatography. The architecture of the wall was investigated with sequential enzyme digestion and electron microscopy. The outer wall surface is covered by a mucilage that is removcd by the isolation procedure. The wall fraction could be completely degraded by extraction in warm I M-KOH followed by digestion with a mixed /,'-glucanase and then chitinase. The outer layer of KOHsoluble glucan is amorphous and or variable thickness. Incubation with glucanase did not change the dimensions of the wall but was necessary before the inner wall was susceptible to attack by chitinase, indicating that />'-glucan does not constitute a separate wall layer but is a matrix associated with the fibrillar chitin. The inner layer presents an even, compact. fibrillar side as the inside surface of the wall, but is looser and uneven outwardly where it interdigitates with the irregular inner surface of the KOH-soluble glucan. Silver hexamide staining showed cystine-containing protein throughout the wall.The fruit body of the Agaricales is massive, yet mainly consists of relatively undifferentiated hyphal elements similar to the vegetative mycelium, and thus provides an interesting system for studying the mechanisms of hyphal aggregation i n morphogenesis. A number of striking correlations between fungal cell form and wall composition, particularly in such phenomena as hyphal-yeast cell type dimorphism, emphasize the importance that wall composition may have in determining dif'ferentiation and rnorphogenesis (Smith & Galbraith, 1971). The composition and architecture of the hyphal wall is now known in a variety of fungi, but a more or less complete picture is available for only one near relative of the mushrooms, Schizopliyllrrm co~iiniuno, a member of the Aphyllophorales. We present here a study of the hyphal architecture 01' the common mushroom, Agirricus bisyorus, and compare and relate it to S. coyIztizunc and the existing fragmentary picture in the Agaricales itself.

show abstract

“…Amino Acids The concentrations of amino acids and peptides were estimated by the Cu ++ salt method of Spies (1957). Glycine was used as the standard.…”

Section: Determination Of Cellular Contentsmentioning

confidence: 99%

The Efflux of Substances from Frog Ventricles to Sucrose and to Ringer's Solutions

Kloot

Dane

1964

The Journal of General Physiology

View full text Add to dashboard Cite

The frog ventricle in sucrose solution contracts for several hours at 25°C, and for as long as 24 hours at 50°C. The possibility that a fraction of the extracellular fluid remains outside of the excitable membrane was examined by measuring the efflux of tracers. The half-time for the efflux to sucrose solution at 25 0 C of C 4 sucrose is about 1 minute, for Na 24 is 6.5 minutes, and for C18 is 4 minutes. There is no evidence for the retention of an extracellular Na fraction. The Qo for Na and C1 effiux is about 1.3. The half-time for K42 efflux is about 180 minutes; the Q,0 is 1.7. The effiux rates of Na 2 4 , C136, and K 42 to sucrose and to Ringer's solutions are quite similar. Ca" 4 efflux is only one-fifth as fast to sucrose solution as to Ringer's; the retention of Ca + + may be important for maintaining excitability in sucrose solution. P efflux is five times faster to sucrose solution than to Ringer's solution, and there is a similar increase in the rate of inosine loss to sucrose solution. The Qo for efflux to sucrose solution is 2.2 for P20 4 and 2.4 for inosine. We suggest that energy metabolism is abnormal in ventricles in sucrose solution and that low temperature prolongs excitability by slowing the metabolic change.A frog heart immersed in isotonic sucrose solution continues to conduct action potentials and to contract for several hours (Singh, Sehra, and Singh, 1945;Singh, 1962;Van der Kloot and Rubin, 1962). This observation raises obvious difficulties for ideas about the inflow of Na + generating the action potential, and about the inflow of Ca + + triggering contraction. The simplest explanation would be that as long as the muscle remains active the sucrose solution does not completely replace the extracellular fluid. This possibility is now examined by measuring the ion contents of sucrose-soaked ventricles and the kinetics of the efflux of radioactive ions and certain other substances from cardiac muscles into sucrose and Ringer's solutions.A second observation was also kept in mind when designing the experiments.

show abstract

[76] Colorimetric procedures for amino acids

Cited by 352 publications

References 12 publications

Interaction of Light Intensity and Soil Temperature With Phosphorus Inhibition of Vesicular‐arbuscular Mycorrhiza Formation

Interaction of Light Intensity and Soil Temperature With Phosphorus Inhibition of Vesicular‐arbuscular Mycorrhiza Formation

Chemistry and Architecture of the Mycelial Wall of Agaricus bisporus

The Efflux of Substances from Frog Ventricles to Sucrose and to Ringer's Solutions

Contact Info

Product

Resources

About