THE NATURE OF PHOTOSYNTHATE IN PINUS STROBUS SEEDLINGS

1962 ◽  
Vol 40 (5) ◽  
pp. 669-676 ◽  
Author(s):  
T. Shiroya ◽  
G. Krotkov ◽  
C. D. Nelson ◽  
V. Slankis
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Organic Acids ◽  
Organic Acid ◽  
Pinus Strobus ◽  
Insoluble Residue ◽  
Two Dimensional ◽  
Initial Separation ◽  
Exchange Resins ◽  
Soluble C

Representatives of C14-labelled sugars, amino acids, and organic acids were placed on several different kinds of exchange resins and their absorption and elution from such resins was determined. From the data obtained, a combination of IR 120 in the H+ form and IRA 400 in the formate form was selected for the initial separation of pine extracts into their sugar, amino acid, and organic acid fractions. These fractions were resolved further by two-dimensional paper chromatography.Two-year-old Pinus strobus seedlings were illuminated in C14O2 for 8 hours either at 2500 or 250 ft-c. Then their shoots were extracted with 80% ethanol and the distribution of C14 in various components of the photosynthate was determined, as described above.The results obtained were essentially the same for seedlings illuminated either with 2500 or 250 ft-c. Not more than 10% of the absorbed C14 were found in the ethanol-insoluble residue. About 98% of the ethanol-soluble C14 were found in the sugar fraction, with the remaining 2% being about equally divided between the amino and organic acids. Sucrose formed about 75% of the sugar fraction, with glucose and fructose making up additional 20%. Only small amounts of raffinose were found.

105 Feed Additives That Optimize Nitrogen Bio-availability in Nursery Pigs Fed Reducing Crude Protein Diets

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 103-103
Author(s):  
Tsung Cheng Cheng Tsai
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Organic Acids ◽  
Organic Acid ◽  
Crude Protein ◽  
Nutrient Digestibility ◽  
Nutrient Absorption ◽  
Feed Additives ◽  
Peptide Transporter ◽  
Amino Acid Requirement

Abstract Reducing dietary crude protein in early nursery has been suggested as a way to conquer the challenge of post-weaning diarrhea. In order to meet the amino acid requirement in RCP diets, feed grade amino acids are typically used, but the detrimental effect on growth performance associated with the aggressive usage of these amino acids resulted in the establishment of dietary limits. Given the fact that protein deposition rate is the highest in young pigs, lower amino acid consumption could slow the growth rate and feed efficiency in early nursery phase. Therefore, identifying feed additives that increase nutrient retention not only can further reduce dietary nitrogen but also maintain GI tract health. Among all feed additives that exert improvements on nutrient digestibility, peptide and organic acids will be discussed here. Peptide, a di- tri amino acid, is absorbed more efficiently than free amino acids in the small intestine through a peptide transporter at the enteric site. In addition, aside from meeting the amino acid requirement, the bioactive peptide possesses functions such as antimicrobial, antioxidant, anti-inflammatory, and as a stimulated Peptide transporter associated with nutrient absorption. Hence, a dietary peptide can help pigs meet the nutrient requirement in RCP diets. Organic acids, on the other hand, have been found to lower gastric pH which improves nutrient absorption, alters microbiome structure (via bacteriostatic and bactericidal) and promotes the growth and health of animals. In addition, organic acids are a ready energy source which is especially critical since nutrient supply disruption, due to low intake during early weaning, is commonly found in weaning pigs. It is noteworthy that variations of growth-promoting effects do exist for both peptide and organic acid products. Thus, understanding the mode of action and response of dietary peptide and organic acid supplements when used across different farm settings is important to help producers decide when to transfer to an antibiotic-free, low zinc operation.

EDTA-promoted exudation of 14C-labeled compounds from detached cottonwood and bean leaves as related to translocation

1977 ◽  
Vol 7 (2) ◽  
pp. 277-284 ◽  
Author(s):  
Richard E. Dickson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Organic Acids ◽  
Organic Acid ◽  
Sieve Tube ◽  
Total Activity ◽  
Mature Leaves ◽  
Edta Solution ◽  
Chloroform Methanol ◽  
Bean Leaves

Mature and developing cottonwood (Populusdeltoides Bartr.) and bean (Phaseolusvulgaris L.) leaves were photosynthetically labeled for 30 min with 14CO2. Radioactive compounds in exudate obtained by placing the cut petioles in 20 mM Na2EDTA for 6 h were compared with those found in chloroform–methanol–water extracts of leaf lamina and petiole. Of the total activity lost in 6 h, 54% was recovered in the exudate from mature bean leaves compared with 3% recovered from cottonwood leaves. Smaller amounts were recovered in exudate from developing leaves compared with mature leaves of both species. Thus EDTA was not very effective for maintaining translocation rates in excised cottonwood leaves. Most of the radioactivity in the exudate was in sugars, indicating relatively pure sieve tube contents. However, radioactive amino acids and organic acids were always present, particularly in exudate from developing leaves. These amino and organic acids could either be derived from metabolism outside of the phloem with subsequent leakage into the EDTA solution, or be a component of the normal translocation stream. Of the total activity in exudates from developing cottonwood leaves, 17% was found in the amino acid and 33% was found in the organic acid fraction compared with 7% and 5% in these fractions, respectively, from developing bean leaves. The distribution of activity in the sugar, amino acid, and organic acid fractions of cottonwood petiole extract was similar to that found in the exudate. In contrast, proportionally less sugar and more amino acids and organic acids were labeled in bean petiole extract compared with the exudate, indicating lateral movement and metabolism in the bean petiole.

The Xylem Sap of Maize Roots: Its Collection, Composition and Formation

1988 ◽  
Vol 15 (4) ◽  
pp. 557 ◽  
Author(s):  
MJ Canny ◽  
ME Mccully
Keyword(s):  
Amino Acids ◽  
Organic Acids ◽  
Organic Acid ◽  
Aspartic Acid ◽  
Xylem Sap ◽  
Great Variability ◽  
Reduced Pressure ◽  
Transpiration Stream ◽  
Maize Roots ◽  
Total Amino Acids

Three methods of sampling xylem sap of maize roots were compared: sap bleeding from the stem cut just above the ground; sap bleeding from the cut tops of roots still undisturbed in the ground; and sap aspirated from excavated roots under reduced pressure. The bleeding saps were often unobtainable. When their composition was measured with time from cutting, the concentrations of the major solutes approximately doubled in 2 h. Aspirated sap was chosen as the most reliable sample of root xylem contents. Solute concentrations of the saps showed great variability between individual roots for all solutes, but on average the concentrations found (in �mol g-1 sap) were: total amino acids, 1.8; nitrate, 1.8; sugars (mainly sucrose), 5.4; total organic acids, 18.3. Individual amino acids also varied greatly between roots. Glutamine, aspartic acid and serine were generally most abundant. The principal organic acid found was malic, approximately 8 �mol g-1. From these analyses the ratios of carbon in the fractions (sugars : amino acids : organic acids) = (44 : 6 : 50). 14Carbon pulse fed to a leaf appeared in the root sap within 30 min, rose to a peak at 4-6 h, and declined slowly over a week. During all this time the neutral, cation and anion fractions were sensibly constant in the proportions 86 : 10 : 4. The 14C therefore did not move towards the equilibrium of 12C-compounds in the sap. It is argued that the results do not support a hypothesis of formation of amino carbon from recent assimilate and reduced nitrate in the roots and an export of this to the shoot in the transpiration stream.

The Formation of Homoserine from Methionine in Germinating Peas

1971 ◽  
Vol 49 (7) ◽  
pp. 795-798 ◽  
Author(s):  
D. R. Grant ◽  
E. Voelkert
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Amino Acid ◽  
Organic Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Total Activity ◽  
Acid Fraction ◽  
Direct Pathway ◽  
Pea Seedlings

L-Methionine-1-14C was fed through the roots to 6-day-old pea seedlings. After 10 h over 80% of the absorbed radioactivity was recovered in the free amino acid fraction, 8% in the extracted proteins, 5% as carbon dioxide, and 2.2% in the organic acid fractions. Analysis of the amino acids revealed that only 24% of the total activity was recovered as methionine, 40% as homoserine, 10% as isoleucine, and smaller but significant amounts of aspartate, O-acetylhomoserine, and cystathionine. Dilution values strongly imply that aspartate is not an intermediate in the extensive conversion of methionine to homoserine; rather a more direct pathway is involved.

Two-dimensional classification of amphiphilic monomers based on interfacial and partitioning properties. 2. Amino acids and amino acid residues

2006 ◽  
Vol 284 (6) ◽  
pp. 575-585 ◽  
Author(s):  
Ivan M. Okhapkin ◽  
Andrei A. Askadskii ◽  
Vladimir A. Markov ◽  
Elena E. Makhaeva ◽  
Alexei R. Khokhlov
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Two Dimensional ◽  
Amino Acid Residues ◽  
Dimensional Classification

TRANSLOCATION OF THE PRODUCTS OF PHOTOSYNTHESIS TO ROOTS OF PINE SEEDLINGS

1962 ◽  
Vol 40 (8) ◽  
pp. 1125-1135 ◽  
Author(s):  
T. Shiroya ◽  
G. R. Lister ◽  
G. Krotkov ◽  
C. D. Nelson ◽  
V. Slankis
Keyword(s):  
Amino Acid ◽  
Pinus Strobus ◽  
Root Systems ◽  
Insoluble Residue ◽  
Artificial Light ◽  
Closed Chamber ◽  
Full Sunlight ◽  
Pine Seedlings ◽  
Artificial Illumination ◽  
Soluble Fractions

Pinus strobus or P. resinosa seedlings, 2 or 3 years old, were illuminated in a closed chamber for 1 hour in the presence of C14O2. This was followed by various periods up to 24 hours under different conditions of light and darkness. Then each seedling was divided into its shoot, stem, and roots, and these were extracted separately with 80% ethanol. The extracts were resolved first on resins into sugar, amino acid, and organic acid fractions and then resolved further by paper chromatography. The C14 content of various fractions and of the eluted compounds was determined by plating and counting their aliquots. Ethanol-insoluble residue was oxidized and counted as BaC14O3.Eight hours after administration of the C14O2, 91 to 94% of the total C14 was found in the ethanol-soluble fractions of shoot, stem, or root. In shoots sugars were found to represent more than 95% of the ethanol-soluble photosynthate, with sucrose forming three-quarters of it. In stem and roots sucrose represented from 75 to 94% of the translocated photosynthate. Raffinose, glucose, and fructose were present in both stem and root.Seedlings with poorly developed root systems translocated less photosynthate to roots than those with good roots. Seedlings, which prior to the experiments were grown in full sunlight or 2500 ft-c artificial illumination translocated more photosynthate to roots than those grown in 6% of full sunlight or 250 ft-c artificial light. Stronger light during translocation itself also had a slight stimulatory effect.Seedlings, which were illuminated in the presence of C14O2 for 1 hour and then retained in a closed chamber for a further period of 7 hours, translocated a larger fraction of absorbed C14 to their roots than comparable seedlings transferred to air after feeding C14O2.

Translocation and Metabolism of MAA-14C in Johnsongrass and Cotton

Weed Science ◽  
1969 ◽  
Vol 17 (4) ◽  
pp. 421-427 ◽  
Author(s):  
M. M. Sckerl ◽  
R. E. Frans
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Gossypium Hirsutum ◽  
Organic Acid ◽  
Biosynthetic Pathway ◽  
Sorghum Halepense ◽  
Acid Fraction ◽  
Methanol Extracts ◽  
Xylem Tissue

Radioautographs showed that root uptake of14C-methanearsonic acid (MAA-14C) by johnsongrass (Sorghum halepense(L.) Pers.) from nutrient solution was rapid and translocation into all portions of the plant occurred within 4 hr after treatment. Basipetal and acropetal translocation of foliar and stem-applied MAA-14C occurred in both johnsongrass and cotton (Gossypium hirsutumL., var. Rex smooth leaf), indicating that movement of the herbicide probably occurs in both phloem and xylem tissue. However, acropetal movement of MAA in both plants occurred at a higher rate than basipetal movement, and basipetal movement in cotton was not as rapid as in johnsongrass. Methanol extracts of MAA-14C johnsongrass were chromatographed. Radioactive spots with Rfvalues different from the MAA-14C standard were observed. Use of location reagents on the chromatographs suggested that MAA-14C may complex with either a sugar or organic acid or both. Amino acid fractions were prepared from methanol extracts of both plants. An MAA metabolite, with a positive reaction to ninhydrin, was located on chromatographs spotted with the amino acid fraction from johnsongrass but was not present in the cotton fraction. A comparison of Rfvalues suggests that the metabolite may be a combination of the MAA molecule with histidine or one of its analogues. Spectrophotometric determination showed a build-up of amino acids in MAA-treated johnsongrass but not in cotton. The increased levels of amino acids in johnsongrass suggest that the MAA metabolite may be blocking a protein synthesis pathway, or some other unknown biosynthetic pathway.

Photosynthetic 14C-labeling patterns in developing soybeans

1973 ◽  
Vol 51 (8) ◽  
pp. 1505-1512 ◽  
Author(s):  
R. D. Noble ◽  
D. W. Long ◽  
J. W. Burley
Keyword(s):  
Amino Acids ◽  
Glycine Max ◽  
Amino Acid ◽  
Age Groups ◽  
Insoluble Residue ◽  
Controlled Environment ◽  
Age Group ◽  
Seed Age ◽  
Soybean Plants ◽  
14C Labeling

Soybean plants (Glycine max 'Harasoy') were cultured in a controlled environment room and studied at seven ages ranging from 16 to 40 days after flowering. Fruits from each age group were labeled by translocation of organic compounds from leaves which had photosynthetically incorporated 14CO2. Leaf blades, petioles, and seeds were extracted in boiling ethanol at the termination of labeling experiments. Seeds were also harvested and extracted 1, 2, and 8 days after labeling. Distribution of label in leaf blades and petioles was essentially the same in all age groups with more than 90% of the activity in petioles being found in carbohydrates. Little or no translocation of amino acids and organic acids was occurring. In seeds, most of the label appeared in the carbohydrate fraction immediately after labeling; however, at 2 and 8 days after labeling the label seemed to be transferred to lipids and the ethanol-insoluble residue. The rate of transfer decreased as a function of seed age. Levels of activity in the amino acid and organic acid fractions were low in all samples.

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