Nitrogen metabolism of Picea glauca. III. Diurnal changes of amino acids, amides, protein, and chlorophyll in leaves of expanding buds

1968 ◽  
Vol 46 (7) ◽  
pp. 929-937 ◽  
Author(s):  
D. J. Durzan
Keyword(s):  
Amino Acids ◽  
Picea Glauca ◽  
Moisture Stress ◽  
Rapid Expansion ◽  
Soluble Nitrogen ◽  
Diurnal Changes ◽  
Fresh Weight ◽  
Protein Nitrogen ◽  
Fresh Weight Basis ◽  
Diurnal Patterns

In spring, buds of spruce shoots under moisture stress contracted during the day and expanded at night. Increased water supply to roots removed the shrinkage of buds and stimulated rapid expansion. In leaves of buds about to break and under moisture stress, the alcohol-soluble nitrogen, high in arginine content, was maximal at midday, after midnight, and again at noon the next day. As a percentage of the soluble nitrogen, all compounds, except arginine, contributed most at sunset and again at sunrise. Other prominent amino acids included proline, alanine, γ-aminobutyric acid, and the amides glutamine and asparagine. Except for the amides, these and other compounds, present at lower levels, gave diurnal patterns similar on a fresh weight basis to arginine. Values for protein nitrogen were greatest at 2 p.m. followed by an increase of asparagine nitrogen, and again at 4 a.m., followed by an increase of glutamine nitrogen. At night the composition of newly synthesized protein increased significantly in aspartic acid, serine, glycine, alanine, leucine, and isoleucine. Chlorophyll a increased from 2 p.m. to 10 p.m., whereas chlorophyll b was present at lower levels and showed little diurnal variation.

Nitrogen metabolism of Picea glauca. II. Diurnal changes of free amino acids, amides, and guanidino compounds in roots, buds, and leaves during the onset of dormancy of white spruce saplings

1968 ◽  
Vol 46 (7) ◽  
pp. 921-928 ◽  
Author(s):  
D. J. Durzan
Keyword(s):  
Amino Acids ◽  
Picea Glauca ◽  
Weight Basis ◽  
Aminobutyric Acid ◽  
Soluble Nitrogen ◽  
Diurnal Changes ◽  
Fresh Weight ◽  
Fresh Weight Basis ◽  
Plant Parts ◽  
Guanidino Compounds

In late August during the onset of dormancy in spruce, seasonal levels of soluble nitrogen, rich in arginine, were high. On a fresh weight basis, diurnal levels of total soluble nitrogen and most component amino acids in roots, buds, and leaves showed maxima, one at sunrise and another in the afternoon or near sunset.Arginine and glutamine in the different plant parts contributed 44 to 83% to the alcohol-soluble nitrogen. In buds and leaves, percentage of arginine remained high and decreased slightly at midday, whereas in roots a continual drop occurred. In all organs examined, changes in glutamine reflected the double maxima of total soluble nitrogen and were greatest in roots.On a fresh weight basis, most amino acids accumulated at sunrise and near sunset; however a few especially in leaves, increased at midday, e.g. glutamic and aspartic acid, lysine, γ-aminobutyric acid, and serine.Comparison of levels of free guanidino compounds in different organs showed remarkable out-of-phase patterns. Levels of these compounds are known from 14C-arginine studies to be closely related to the metabolism of arginine.

Nitrogen metabolism of Picea glauca. IV. Metabolism of uniformly labelled 14C-L-arginine, [carbamyl-14C]-L-citrulline, and [l,2,3,4-14C]-γ-guanidinobutyric acid during diurnal changes in the soluble and protein nitrogen associated with the onset of expansion of spruce buds

1969 ◽  
Vol 47 (8) ◽  
pp. 771-783 ◽  
Author(s):  
D. J. Durzan
Keyword(s):  
Amino Acids ◽  
Nitrogen Metabolism ◽  
Picea Glauca ◽  
Free Amino ◽  
Neutral Fraction ◽  
Aminobutyric Acid ◽  
Diurnal Changes ◽  
Protein Nitrogen ◽  
Low Levels ◽  
Pool Sizes

In spring as white spruce buds started to expand, seasonal levels of proline were high and pool sizes of most free amino acids were maximal at sunset and sunrise. Uniformly labelled 14C-L-arginine, applied to buds at sunrise, was converted to citrulline via ornithine. [Carbamyl-14C]-L-citrulline was metabolized to argininosuccinate, arginine, and urea. These reactions indicated the presence at low levels of the Krebs–Henseleit or ornithine cycle. No convincing urease activity could be extracted or detected histochemically. Urease, added to extracts of buds exposed to radioactive L-arginine or L-citrulline, released 14CO2 confirming the presence of 14C-urea. L-Arginine was converted readily to ornithine, Δ1-pyrroline-5-carboxylic acid, and proline. The appearance of 14C in monosubstituted guanidines, e.g. γ-guanidinobutyric acid and others, which remained unidentified but proven not to be homoarginine, agmatine, argininic acid, nor γ-guanidinobutyramide, accounted more readily for the metabolism of arginine than did the ornithine cycle alone. L-Citrulline was metabolized via arginine to γ-guanidinobutyric acid and to several unidentified compounds that were not amino acids or related to monosubstituted guanidines. 14C-γ-Aminobutyric acid, a product of arginine degradation, was also derived from [l,2,3,4-14C]-γ-guanidinobutyric acid suggesting the presence of a heteroarginase. γ-Guanidinobutyric acid was translocated down the shoot with little distribution of 14C into other compounds.14C from arginine and citrulline and to a much lesser extent from γ-guanidinobutyric acid was recovered in the protein fraction mainly as arginine, glutamic acid, and proline. Maximal incorporation of 14C into protein was reached at or near midnight, then rapidly fell to noon of the following day. Incorporation of 14C into bud protein was out of phase with levels of total protein N and in phase with an increase of radioactivity in compounds of the anionic and neutral fraction, reflecting dramatically the complexity of the nitrogen metabolism of buds awakening from winter dormancy.

Note. Effect of brining time on proteolytic changes in Idiazábal cheese during ripening / Nota. Cambios proteolíticos durante la maduración del queso Idiazábal por efecto del tiempo en salmuera

1996 ◽  
Vol 2 (5) ◽  
pp. 335-339 ◽  
Author(s):  
F.C. Ibáñez ◽  
A.I. Ordóñez ◽  
M.S. Vicente ◽  
M.I. Torres ◽  
Y. Barcina
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Total Nitrogen ◽  
Free Amino Acids ◽  
Free Amino ◽  
Dry Matter ◽  
Electrophoretic Analysis ◽  
Soluble Nitrogen ◽  
Clear Trend ◽  
Protein Nitrogen

Idiazábal cheeses were made employing brining times of 12 h (batch A) and 36 h (batch B). Proteolytic changes in both batches were examined over 270 d of ripening; proteolysis was low in both batches, but lower in batch B than in batch A. Electrophoretic analysis revealed incom plete breakdown of αs and β-caseins at the end of the ripening period, particularly in batch B. The proportion of soluble nitrogen as a percentage of total nitrogen was 17.55% in batch B and 19.48% in batch A, while the proportion of non-protein nitrogen was 11.78% in batch B and 15.16% in batch A. The proportion of non-protein nitrogen as a percentage of soluble nitrogen was 67.17% in batch B and 77.88% in batch A. The free amino acids, the smallest non-protein nitrogen frac tion, attained values of 1203 mg/100 g of dry matter in batch B and 1902 mg/100 g of dry matter in batch A. After 60 d of ripening, the main free amino acids were glutamic acid, valine, leucine, lysine, and phenylalanine in both batches, although levels were higher in the batch with the shorter brining time. There was no clear trend in the non-protein-forming amino acids with either ripening time or brining time.

scholarly journals Physiology of Pea Fruits I. the Developing Fruit

1955 ◽  
Vol 8 (2) ◽  
pp. 137 ◽  
Author(s):  
HS Mckee ◽  
RN Robertson ◽  
JB Lee
Keyword(s):  
Ascorbic Acid ◽  
Cell Volume ◽  
Starch Content ◽  
Dry Weight ◽  
Metabolic Changes ◽  
Soluble Carbohydrate ◽  
Soluble Nitrogen ◽  
Fresh Weight ◽  
Protein Nitrogen ◽  
Respiration Rates

Pea fruits from two crops were sampled at different times from flowering. Changes in the fresh weight, dry weight, starch, soluble carbohydrate, protein nitrogen, and soluble nitrogen in both seeds and hulls were followed in two seasons and related Jo the changes in cell volume in the seeds. In one season respiration rates and phosphate, pectin, and ascorbic acid contents were also investigated. The seeds gained more carbohydrate and nitrogen than was lost by the hulls. Starch and protein were synthesized rapidly by the seeds. The increase in starch content in the seeds was followed by a decrease in soluble carbohydrate content, after which the seed ceased to accumulate water. These metabolic changes are discussed in the light of recent biochemical knowledge, and in relation to more detailed biochemical investigations in progress.

Nitrogen metabolism of Picea glauca. I. Seasonal changes of free amino acids in buds, shoot apices, and leaves, and the metabolism of uniformly labelled 14C-L-arginine by buds during the onset of dormancy

1968 ◽  
Vol 46 (7) ◽  
pp. 909-919 ◽  
Author(s):  
D. J. Durzan
Keyword(s):  
Amino Acids ◽  
Nitrogen Metabolism ◽  
Picea Glauca ◽  
Seasonal Changes ◽  
Late Summer ◽  
Soluble Nitrogen ◽  
Shoot Apices ◽  
Nitrogenous Compounds ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Metabolism

Buds, shoot apices, and leaves from terminal shoots of white spruce saplings accumulated high levels of alcohol-soluble nitrogen in spring, late summer, and early winter. Major components, e.g. arginine, glutamine and proline, of the soluble nitrogen showed patterns complementary to each other. These changes represented the storage and mobilization of nitrogenous compounds during the onset of dormancy or the growth of shoots. Leaves contained less total soluble nitrogen than buds or shoot apices. Soluble nitrogen and arginine content of leaves resembled buds in their seasonal patterns but changes in aspartic acid, glutamic acid, and alanine were much greater than in buds, especially in late summer.When the first frost appeared, uniformly labelled 14C-arginine, applied to the apices of buds, readily entered newly synthesized protein, and free arginine was converted to proline via ornithine. Proline with carbon derived from arginine also entered proteins that were metabolized at different rates. A fraction of the proline in protein was hydroxylated to hydroxyproline. Although traces of 14C-citrulline were detected, more carbon was metabolized to free guanidino compounds, e.g. α-keto-δ-guanidinovaleric acid, γ-guanidinobutyric acid, and several monosubstituted guanidines. After 24 hours, labelled arginine, proline, and γ-guanidinobutyric acid moved down the shoot to the leaves. These metabolic changes in buds show that many of the seasonal changes in amino acids are intimately related to the carbon and nitrogen metabolism of arginine.

scholarly journals Characteristic of the nutritive value of the protein from rye caruopses. I. Amino acid composition of protein and the nitrogen forms in the caryopses of ten rue varieties from the breeding collection

2015 ◽  
Vol 27 (1) ◽  
pp. 105-114 ◽  
Author(s):  
R. Kubiczek ◽  
M. Rakowska
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Protein Content ◽  
Acid Composition ◽  
Nutritive Value ◽  
Dry Weight ◽  
High Protein ◽  
Soluble Nitrogen ◽  
Protein Nitrogen

Total and soluble nitrogen, protein and non-protein -nitrogen was determined as well as the amino acid composition of the caryopses of ten rye varieties including three bred in Poland and cultivated on a commercial scale: 'Dańkowskie Złote', 'Dańkowskie Selekcyjne' and 'Borkowskie Tetra'. and seven foreign varieties characterized by a high total protein content (11.9-16.4% in dry weight). In the varieties examined the amount of protein nitrogen increased in the same degree as did the content of total nitrogen. The amino acids limiting the nutritive value of the protein in rye caryopses were mostly lysine and methionine, and in the varieties with high protein content tryptophan. The low-protein varieties had a relatively higher content of lysine, sulphur amino acids, tryptophan and other amino acids (as % of protein) than the high protein ones, but their absolute amino acid content (as % of dry weight) was lower.

The optimum level of protein in the supplement for dairy cows with access to grass silage

1979 ◽  
Vol 29 (3) ◽  
pp. 283-291 ◽  
Author(s):  
F. J. Gordon ◽  
C. H. McMurray
Keyword(s):  
Protein Content ◽  
Milk Yield ◽  
Crude Protein ◽  
Weight Basis ◽  
Optimum Level ◽  
Dry Matter Content ◽  
Fresh Weight ◽  
Protein Nitrogen ◽  
Fresh Weight Basis ◽  
Grass Silage

ABSTRACTGrass silage with a dry-matter content of 19·4% and containing 16·7% crude protein was offered ad libitum to 42 first lactation British Friesian cows during the first 75 days post-calving. In addition the animals received supplementary concentrates containing either 10·3, 13·6, 17·3, 21·1, 25·2 or 30·3% crude protein on a fresh weight basis, with extracted soya bean meal being used as the main protein source. All concentrates were offered at an equal level of 8·0 kg per day. The relationship between milk yield and protein content of the supplement was curvilinear and was described by the following equation:Y= 8·95+ 1·0×–0·0205×where Y = milk yield per day in kg, and × = percentage protein in the supplement. This equation indicated that maximum milk yield was obtained with a concentrate containing 24·4 % protein on a fresh weight basis. The protein content of the milk was also curvilinearly affected by the level of protein in the supplement, and it was calculated that maximum milk protein (nitrogen × 6·38) would be obtained with a supplement containing 23·9% protein. Plasma blood urea levels increased linearly with increasing protein intake. The effects on live-weight change and blood components were also recorded.

Effect of droughting and chilling on maturation and chemical composition of Townsville Stylo (Stylosanthes humilis)

1971 ◽  
Vol 22 (3) ◽  
pp. 369 ◽  
Author(s):  
CT Gates ◽  
WT Williams ◽  
RD Court
Keyword(s):  
Amino Acids ◽  
Nutrient Content ◽  
Major Effect ◽  
Multivariate Techniques ◽  
Soluble Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Protein Nitrogen ◽  
Stylosanthes Humilis ◽  
Dry Conditions ◽  
Townsville Stylo

The effects of droughting and chilling on maturing Townsville stylo plants was assessed in terms of growth, seed and leaf shed, nitrogen, phosphorus, and amino acid composition. The major effect was due to droughting. Temperature participated as a small temperature-droughting interaction, in that cold reduced growth and increased proline under moist, but not under dry conditions. With droughting under warm conditions seed and leaf shed were increased and the nutrient content of seed was raised, which resulted in more of the plant's nitrogen and phosphorus being lost in these fractions. Droughting increased soluble nitrogen at the expense of protein nitrogen, but the amino acids fell as a proportion of the soluble nitrogen. The interrelations of nine amino acids were examined by multivariate techniques and it was shown that proline and aspartic acid behaved atypically, and that while other amino acids fell, proline increased some 10-fold under drought or cold stress. These effects indicate that soluble nitrogenous components may both increase and change in composition in the maturing plant as a result of stress, so rendering the plant more susceptible under field conditions to leaching or breakdown caused by dew or by slight showers of rain.

scholarly journals The effect of sulphur deficiency and sulphur fertilisation on the nitrogen compounds of timothy

1978 ◽  
Vol 50 (2) ◽  
pp. 137-146
Author(s):  
Terttu Ettala ◽  
Matti Kreula ◽  
Hilkka Tähtinen
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Total Nitrogen ◽  
Free Amino Acids ◽  
Free Amino ◽  
Nitrate Nitrogen ◽  
Nitrogen Compounds ◽  
Soluble Nitrogen ◽  
Protein Nitrogen ◽  
Sulphur Deficiency

The effect of sulphur deficiency and sulphur fertilisation on the nitrogen compounds of plants was studied, using timothy as the test species. The samples were obtained from 4 field trials performed in northern Finland. The nitrogen and sulphur treatments in each of these trials were as follows: a) N O, S O, b) N 48, S O, c) N 48, S 34, d) N 96, S O and e) N 96, S 68 kg/ha. Nitrogen was applied as NPK compound fertiliser and sulphur in the form of gypsum. In trials 1and 2 sulphur given in addition to nitrogen increased the yield considerably. The contents of soluble-, protein-, a-amino-, ammonium- and nitrate-nitrogen, as well as the free and peptide- and protein-bound amino acids were determined in the harvested timothy. Nitrogen fertilisation did not have any noticeable effect on the protein-nitrogen content of sulphur-deficient plants, but sulphur fertilisation increased it by an average of 26 % (trial 2). The proportion of soluble nitrogen of the total nitrogen in trials 1 and 2 averaged 50 % with N-fertilisation and 37 % with N+S fertilisation. Sulphur fertilisation decreased the contents of a-amino-, ammonium- and nitrate-nitrogen, and also their proportions of the total nitrogen. In those trials (3 and 4) in which sulphur fertilisation did not increase the yield, the proportion of soluble nitrogen of the total nitrogen was an average of 33 % with all treatments. In sulphur-deficient timothy the content of asparagine and aspartic acid totalled 60 % of the content of free amino acids, and their nitrogen formed about 17% of the total plant nitrogen. The corresponding figures with sulphur fertilisation were 39 % and 3.5 %, and in those trials where there was no sulphur deficiency (trials 3 and 4) on average 27 % and 2.5 %, irrespective of fertilisation. The proportion of soluble nitrogen of the total nitrogen of timothy was closely correlated (r = 0.79***) to the N/S ratio, as was the proportion of asparagine plus aspartic acid of the total free amino acids (r = 0.91***).

scholarly journals Starch Synthesis and Changes in Uridine Diphosphorlase in the Developing Wheat Grain

1969 ◽  
Vol 22 (6) ◽  
pp. 1321 ◽  
Author(s):  
JF Turner
Keyword(s):  
Reducing Sugars ◽  
Starch Synthesis ◽  
Dry Weight ◽  
Soluble Nitrogen ◽  
Wheat Grain ◽  
Fresh Weight ◽  
Sharp Rise ◽  
Protein Nitrogen ◽  
Starch Formation ◽  
Main Substrate

The enzymes UDPG pyrophosphorylase and ADPG pyrophosphorylase were assayed during the growth of wheat grains. Changes in fresh weight, dry weight, water, sucrose, reducing sugars, starch, total nitrogen, protein nitrogen, and soluble nitrogen were followed simultaneously. Throughout development the activity of UDPG pyrophosphorylase per grain was much greater than the activity of ADPG pyrophosphorylase. Both enzymes increased in activity during the phase of starch synthesis and a sharp rise in ADPG pyrophosphorylase was associated with the onset of rapid starch formation. ADPG pyrophosphorylase activity decreased to a very low level when starch formation in the grain ceased. UDPG pyrophosphorylase activity also decreased at this time. Although the participation of UDPG is not excluded, it is suggested that the main substrate for starch synthesis in the wheat grain is ADPG. A mechanism for the synthesis of starch from sucrose is proposed.

Sign in / Sign up

Export Citation Format

Share Document