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.

Xylem translocation of amino acids from roots to shoots in cottonwood plants

1979 ◽  
Vol 9 (3) ◽  
pp. 374-378 ◽  
Author(s):  
Richard E. Dickson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Organic Acids ◽  
Xylem Sap ◽  
Aminobutyric Acid ◽  
Acid Fraction ◽  
Root Pressure ◽  
Xylem Exudate ◽  
And Storage ◽  
Total Amino Acids

Xylem sap produced by root pressure and collected from topped cottonwood (Populusdeltoides Bartr.) contained sugars, organic acids, amino acids, protein, and inorganic nutrients. Amino acids and NO3N were present at the highest concentrations. Total amino acids in xylem sap ranged from 3 to 10 mol m−3 and NO3N ranged from 7 to 10 mol m−3. When lower leaves were photosynthetically labeled with 14CO2, activity was rapidly translocated to roots and recycled to shoots. Within 6 h after labeling leaves, xylem exudate contained between 1 and 2 × 106 disintegrations min−1 cm−3. Most of the activity (50 to 70%) was in the amino acid fraction. Although nine amino acids contained some activity, more than 90% of the 14C was found in five common transport and storage amino acids: asparagine, glutamine, serine, alanine, and γ-aminobutyric acid. Glutamine contained 60 to 70% of the activity in the amino acid fraction 2 h after topping. Sugars, translocated from lower leaves to roots via the ploem, are converted to amino acids in roots and then translocated to the developing shoot via the xylem.

scholarly journals Effect of Two Strains of Peanut Mottle Virus on Fatty Acids, Amino Acids, and Protein of Six Peanut Lines1,2

1979 ◽  
Vol 6 (2) ◽  
pp. 88-92 ◽  
Author(s):  
Allan R. Hovis ◽  
Clyde T. Young ◽  
Cedric W. Kuhn
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Aspartic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Mottle Virus ◽  
Peanut Seed ◽  
Mild Strain ◽  
Arachis Hypogaea L ◽  
Total Amino Acids

Abstract Peanut (Arachis hypogaea L.) cultivars (Starr and Florunner) and four peanut introductions (PI 261945, 261946, 261973, and 261980) were each separately inoculated with a mild strain (M2) and with the necrosis strain (N) of peanut mottle virus. The effects of these viral strains on the chemical composition of peanut seed were evaluated. The chemical characteristics varied with the type of viral infection. The greatest effect was on fatty acids and the least on the total amino acids. In general, peanuts infected with the necrosis strain showed: (1) a decrease in the percentages of stearic and oleic acids, while linoleic, arachidic, behenic, and lignoceric acids increased, (2) increases in the levels of the free amino acids glycine, alanine, isoleucine, histidine, lysine, and arginine, and (3) the total amino acids exhibited a slight decrease in aspartic acid and a slight increase in methionine. Peanuts infected with the mild strain generallly showed: (1) a slight increase in linoleic acid, (2) little effect on the free amino acids, and (3) a small increase in tyrosine and a slight decrease in serine and aspartic acid for the total amino acids. No treatment effect was noted on protein content.

Effect of Salinity on Photosynthetic 14CO2 Fixation and Amino Acid Pools of Bellerochea yucatanensis (v. Stosch) and Thalassiosira rotula (Meunier)

1985 ◽  
Vol 40 (7-8) ◽  
pp. 527-530
Author(s):  
Günter Döhler ◽  
Joachim Zink
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspartic Acid ◽  
Marine Diatoms ◽  
14Co2 Fixation ◽  
Low Salt ◽  
Photosynthetic Products ◽  
Sugar Phosphates ◽  
Total Amino Acids

Abstract The marine diatoms Bellerochea yucatanensis and Thalassiosira rotula were grown at different salinities (20/25, 35, and 40/45‰ salinity (S), respectively) under normal air (0.035 vol.% CO2). No significant variations in the percentage of gross photosynthetic products (e.g. total amino acids, sugar phosphates) were found as a function of salinity during growth. The bulk of the soluble 14C-radioactivity was detected in amino acids. 14C-labelling of glutamine increased markedly with salinity. Low salt - grown algae are characterized by enhanced amino acid pools, mainly of aspartic acid, asparagine and glutamine. It was found that the tested amino acids are not involved in osmoregulation.

The main amino acids in xylem sap of Vitis vinifera L. var. Cabernet Franc during the vegetative cycle. Search for an amino acid marker

OENO One ◽  
1999 ◽  
Vol 33 (2) ◽  
pp. 49
Author(s):  
Corine Larchevêque ◽  
A. Casanova
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspartic Acid ◽  
Acid Content ◽  
Xylem Sap ◽  
Amino Acid Content ◽  
Total Amino Acid ◽  
Bud Burst ◽  
Phenological Stage ◽  
Total Amino Acid Content

<p style="text-align: justify;">Numerous studies have been carried out on the vine, must and wine, but few on sap. Main phenological stages i.e. bud burst, the flowering period, veraison and the ripening period have been well described. However, at the present time, no study is available identifying the main amino acids of the xylem sap, at the formentioned periods. Located within the « Graves de Pessac-Léognan » vineyard, the plot area studied has a clayey-chalky soil with a small amount of sand present. The cultivar Cabernet franc was grafted on the Fercal rootstock. Planted in June 1982, the vine was trained with Guyot pruning and no tillage. The density of the plantation was 5.550 vines per ha. Four rows of 21 vines were sampled.</p><p style="text-align: justify;">Analysis of xylem sap, by H.P.L.C., at the four stages, taken from several vintages, showed that the global content of amino acids varied year to year (LARCHEVÊQUE, 1998). The experiment reported on herein was carried out in order to determine both the main amino acids in the xylem sap and to identify a marker amongst them, having the same evolution as that of the global amino acid content from one phenological stage to the next. A pool of eight amino acids, all present in large quantities (about 80 p. cent of total amino acid content), was always noted : asparagine/glutamine, tyrosine, arginine, aspartic acid, glutamic acid, histidine and proline. Concentration levels of these components differed in sap, depending on the vintage, at the same phenological stage. At bud burst, as at the flowering period, the sap had a similar qualitative composition.</p><p style="text-align: justify;">It was noteworthy that aspartic acid evidenced the same evolution that of the total amino acid content (i.e. the same variation in percentage) from one phenological stage to the next. Aspartic acid should therefore be regarded as a « marker » of total amino acid content evolution during the vegetative cycle.</p>

Nitrogenous compounds in the xylem sap of American elms with Dutch elm disease

1969 ◽  
Vol 47 (7) ◽  
pp. 1061-1065 ◽  
Author(s):  
Dilbagh Singh ◽  
Eugene B. Smalley
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Butyric Acid ◽  
Total Concentration ◽  
Xylem Sap ◽  
Dutch Elm Disease ◽  
Amide Nitrogen ◽  
Nitrogenous Compounds

Thirty-two ninhydrin-positive nitrogenous compounds were present in the xylem sap of 6- to 9-year- old American elms. Twenty-six of these compounds were identified. Total concentration of nitrogenous materials was several times higher in diseased than in healthy sap after inoculation during the susceptible period in the spring, but was lower after inoculations during the late resistant period. Percentage compositions of γ-amino-n-butyric acid, proline, and alanine in diseased sap increased after both spring and mid-summer inoculations. Proline, which was present in trace amounts in healthy sap, constituted 14 to 38% of the total in diseased sap. Percentage concentrations of amide nitrogen in diseased sap were reduced 50% or more in all inoculated trees. Percentages of ammonia, aspartic acid, glutamic acid, and several other amino acids did not change.

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.

Digestibility of protein, amino acids and starch in mink (Mustela vison) fed diets processed by different extrusion conditions

2004 ◽  
Vol 84 (4) ◽  
pp. 673-680 ◽  
Author(s):  
K. Ljøkjel ◽  
M. Sørensen ◽  
T. Storebakken ◽  
A. Skrede
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Crude Protein ◽  
Control Diet ◽  
Processing Parameters ◽  
Effect Of Temperature ◽  
Protein Amino Acid ◽  
Isoleucine Leucine ◽  
Total Amino Acids

An experiment was carried out to evaluate the effect of different extrusion processes on digestibility of a fish-meal-based diet fed to mink. The feed was processed in a twin-screw extruder with the exit temperatures of the meal of 100, 125 or 150°C. Feed production was carried out three times, using different extrusion conditions to achieve the target temperatures. An untreated meal mixture was included as a control diet. True digestibilities of crude protein and total amino acids were lower for diets extruded at 125 and 150°C than for the control (P < 0.05). Digestibilities of crude protein, total amino acids, and the amino acids alanine, arginine, aspartic acid, cysteine, glutamic acid, histidine, isoleucine, leucine, lysine and valine decreased when increasing extrusion temperature from 100 to 125 °C (P < 0.05), a further increase in temperature did not influence digestibility (P > 0.05). The highest reduction was seen for cysteine (6.8 percentage units). Starch digestibility was increased by extrusion, but there was no effect of temperature (P > 0.05). Digestibilities of crude protein, total amino acids, alanine, arginine, aspartic acid, glutamic acid, glycine, proline, histidine, lysine, tryptophan and valine were affected by the processing method (P < 0. 05), which, by multivariate analysis, was revealed to be associated mainly with processing parameters: revolutions per minute, conditioner temperature, die temperature and feeding rate. Digestibility of starch was influenced mainly by the addition of water. Key words: Digestibility, protein, amino acid, starch, mink, extrusion

Chemical Composition of Canadian Apple Juice

1972 ◽  
Vol 55 (5) ◽  
pp. 1104-1108 ◽  
Author(s):  
J J Ryan
Keyword(s):  
Amino Acids ◽  
Chemical Composition ◽  
Organic Acids ◽  
Organic Acid ◽  
Inorganic Phosphate ◽  
Apple Juice ◽  
Fruit Juice ◽  
Soluble Solids ◽  
Phosphate Content ◽  
Useful Components

Abstract Twenty-one samples of authentic apple juice have been studied. Analytical values are presented for amino acids, pH, density, soluble solids, potassium, ash, individual organic acids, and individual sugars. These values are compared to those obtained from 11 samples of apple juice from local markets. It has been found that the potassium, ash, and organic acid patterns are the most useful components to characterize this juice. A facile method is also described for measuring inorganic phosphate content of fruit juice.

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