scholarly journals Analysis of Ratio-based Responses

2007 ◽  
Vol 132 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Timothy L. Righetti ◽  
David R. Sandrock ◽  
Bernadine Strik ◽  
Carmo Vasconcelos ◽  
Yerko Moreno ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Dry Weight ◽  
Fertilization Rate ◽  
N Fertilizer ◽  
Foliar N ◽  
Almond Trees ◽  
The Relationship ◽  
Total Amino Acids

It is not appropriate to compare ratio-based expressions for different cultivars or treatments if a plot of the denominator versus the numerator of a ratio-based expression has a nonzero y-intercept and the values for either the denominators or numerators differ with cultivars or treatments. Whenever nonzero y-intercepts are encountered, the value for a ratio-based expression will be dependent on both the denominator and numerator. The “ratio problem” is demonstrated with shoot N concentration in blueberries (Vaccinium corymbosum L.) and amino acid accumulation in almonds [Prunis dulcis (Mill.) D.A. Webb]. Data were collected from the first and second growth flush of blueberry shoots on plants that were at two in-row spacings and two rates of N fertilizer. Free amino acid:total amino acid ratios were measured in dormant almond trees fertilized at different rates with and without foliar N supplements. Functions describing the relationship between dry weight and total N content in blueberry tissues have positive y-intercepts for both N fertilizer application rates. Functions describing the relationship between total amino acids and free amino acids in almond trees have a negative y-intercept. Differences attributable to fertilization rate in blueberries probably were the result of differences in N uptake and N utilization, but the effects of spacing and growth flush are indirect and can be accounted for by differences in dry weight. Likewise, effects of fertilization rate and foliar N supplement in almonds are indirect and can be accounted for by differences in the total amino acids in dormant trees. With regression one can determine if the relationship between the denominator and numerator differs for the groups or treatments being studied. When an analysis of covariance is used to account for differences in the denominators of ratio-based expressions, results are consistent with the regression analysis. When a conclusion is based on statistical differences of a ratio-based expression, it is the researcher's responsibility to determine whether these effects are direct or indirect.

scholarly journals Free and Total Amino Acid Composition of Maturing Seed from Six Peanut (Arachis hypogaea L.) Cultivars

1980 ◽  
Vol 7 (1) ◽  
pp. 32-37 ◽  
Author(s):  
S. M. M. Basha ◽  
J. P. Cherry ◽  
C. T. Young
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Arachis Hypogaea ◽  
Free Amino Acids ◽  
Free Amino ◽  
Dry Weight ◽  
Rate Of Change ◽  
Arachis Hypogaea L ◽  
Peanut Cultivars ◽  
Total Amino Acids

Abstract Maturing seeds of six peanut cultivars (Arachis hypogaea L.) varying in protein content at maturity showed differences in rate of change of dry weight, crude protein, and free and total amino acids. Seeds of the high-protein cultivars increased in dry weight and deposited protein at a more rapid rate between immature and low intermediate stages of maturation than did those of the low- and intermediate-protein cultivars. Free amino acid content in seeds classified as low-intermediate maturity from all cultivars was significantly less than was that of those at the immature stage. The greatest change was in seed of the high-protein group. The rate of change of content of selected free amino acids among seed was different for the three groups of cultivars. Similar observations were noted as the content of select total amino acids increased in maturing seeds. Variations in quantities of free amino acids in immature seeds and differences in the rate at which they are incorporated into proteins of seeds from various cultivars suggest that there is genetic variability in the mechanism for synthesis of selected proteins. These differences also indicate the potential for the development of peanut cultivars having seed with nutritionally desirable protein.

scholarly journals Nitrogen Storage and Its Interaction with Carbohydrates of Young Almond Trees in Response to Nitrogen Supply

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 796C-796
Author(s):  
Guihong Bi* ◽  
Carolyn Scagel ◽  
Lailiang Cheng ◽  
Leslie Fuchigami
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Total Amino Acid ◽  
Total N ◽  
N Supply ◽  
N Assimilation ◽  
Predominant Amino Acid ◽  
Total Amino Acids

June-budded `Nonpareil/Nemaguard' almond (Prunus dulcis (Mill) D.A. Webb) trees were fertigated with one of five nitrogen (N) concentrations (0, 5, 10, 15, or 20 mm) in a modified Hoagland's solution from July to September. In October, the trees were sprayed twice with either water or 3% urea, then harvested after natural leaf fall and stored at 2°C. Trees were destructively sampled during winter storage to determine their concentrations of amino acids, protein, and non-structural carbohydrates (TNC). Increasing N supply either via N fertigation during the growing season or with foliar urea applications in the fall increased the concentrations of both free and total amino acids, whereas decreased their C/N ratios. Moreover, as the N supply increased, the proportion of nitrogen stored as free amino acids also increased. However, protein was still the main form of N used for storage. The predominant amino acid in both the free and total amino-acid pools was arginine. Arginin N accounted for an increasing proportion of the total N in both the free and total amino acids as the N supply was increased. However, the proportion of arginine N was higher in the free amino acids than in the total amino acids. A negative relationship was found between total amino acid and non-structural carbohydrate concentrations, suggesting that TNC is increasingly used for N assimilation as the supply of N increases. Urea applications decreased the concentrations of glucose, fructose, and sucrose, but had little influence on concentrations of sorbitol and starch. We conclude that protein is the primary form of storage N, and that arginine is the predominant amino acid. Furthermore, the synthesis of amino acids and proteins comes at the expense of non-structural carbohydrates.

Resistance of different host plants and cultivars of cassava to the mealybug Phenacoccus manihoti: Effect of infestation on leaf extract composition

1995 ◽  
Vol 16 (1) ◽  
pp. 73-81
Author(s):  
M. Tertuliano ◽  
B. Le Rü
Keyword(s):  
Amino Acids ◽  
Antibiotic Resistance ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Leaf Area ◽  
Free Amino ◽  
Dry Weight ◽  
Phenacoccus Manihoti ◽  
Total Dry Weight ◽  
Cassava Varieties

AbstractThe effect of a 2-month infestation by the cassava mealybug (Phenacoccus manihoti Mat. Ferr.) on the metabolism of nitrogen (amino acids) and carbon (carbohydrates), leaf area and total dry weight of five cassava varieties (Manihot esculenta Crantz), faux-caoutchouc (a hybrid of M. esculenta and M. glaziovii Muell, Arg.), poinsettia (Euphorbia pulcherrima Wild) and talinum (Talinum triangulare Jack) was studied. Free amino acid and free sugar contents as well as relative free amino acid composition in the leaf extracts, although found to be very different from one plant to another, were not significantly modified by P. manihoti infestation, except for the total amino acid contents of the cassava variety 30M7. Variations in one particular amino acid induced by mealybug infestation were not linked to the antibiotic resistance of these plants. Infestation by the cassava mealybug did not modify the total dry weight but reduced the total leaf area although this reduction was only significant in cassava varieties 59M2, 30M7 and M'pembe, and in faux-caoutchouc. Within the genus Manihot, the reduction in leaf area was strongly correlated (r= -0.878, P≤0.05) to the degree of antibiotic resistance and was coupled to an increase in the ratio of sugars to amino acids, suggesting a similarity between the effects of water stress and those of mealybug infestation.

Intracellular free amino acid patterns in duodenal and colonic mucosa

1990 ◽  
Vol 36 (2) ◽  
pp. 378-381 ◽  
Author(s):  
G Ollenschläger ◽  
K Langer ◽  
H M Steffen ◽  
M Schrappe-Bächer ◽  
H Schmitt ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Dry Weight ◽  
Essential Amino Acids ◽  
Medical Patients ◽  
The Mean ◽  
First Time ◽  
Duodenal Biopsies ◽  
Hiv Negative

Abstract We report for the first time the concentrations of free amino acids in human intestinal biopsies obtained by routinely performed endoscopy. We studied 15 medical patients with no changes of the mucosa and six HIV-infected persons with duodenitis. The mean (and SD) sum of all amino acids, taurine excepted, was 61.9 (5.4) mmol/kg dry weight in duodenal biopsies of HIV-negative subjects (n = 11) and 82.9 (0.6) mmol/kg in colonic specimens: 50% (44%) of the total (minus taurine) consisted of aspartate and glutamate and 14% (12%), of the essential amino acids. The relative amino acid pattern in duodenum and colon differed completely from that for muscle: aspartate was fourfold higher; glutamate, phenylalanine, glycine, valine, leucine, and isoleucine were about twofold higher. In contrast, glutamine amounted only to 4% (duodenum) to 14% (colon) of muscle glutamine. In duodenal biopsies of the HIV-infected persons, we found significantly (P less than 0.01, except glutamine: P less than 0.025) increased concentrations of glutamate (24.1 vs 17 mmol/kg dry weight), ornithine (1.4 vs 0.4), valine (2.2 vs 1.7), and glutamine.

scholarly journals Turkey-Hen Amino Acid Composition of Brain and Eyes

2015 ◽  
Vol 58 (1) ◽  
pp. 30-39
Author(s):  
Emmanuel Ilesanmi Adeyeye
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Isoelectric Point ◽  
Essential Amino Acid ◽  
Meleagris Gallopavo ◽  
Dry Weight ◽  
Essential Amino Acids ◽  
Amino Acids Composition ◽  
The Brain ◽  
Total Amino Acids

The amino acids composition of the brain and eyes of the mature Turkey-hen (Meleagris gallopavo L.),  were determined on dry weight basis. Total essential amino acids ranged from 35.1-36.0 g/100 g as 49.5-49.8% of the total amino acids. The amino acid score showed that lysine ranged from 0.76-0.91 (on whole hen’s egg comparison), 0.85-1.03 (on provisional essential amino acid scoring pattern), and 0.81-0.98 (on suggested requirement of the essential amino acid of a preschool child). The predicted protein efficiency ratio was 1.94-2.41, whilst essential amino acid index range was 1.06-1.08 and the calculated isoelectric point range was 3.97-4.18. The correlation coefficient (rxy) was positively high and significant at r = 0.01 for the total amino acids, amino acid scores (on the whole hen’s egg comparisons made) and the isoelectric point. On the whole, the eyes were better in 12/18 or 66.7% parameters of the amino acids than the brain of Turkey-Hen.

Changes in proteins and free and total amino acids of peanuts (Arachis hypogaea) infected with Aspergillus parasiticus

1975 ◽  
Vol 53 (22) ◽  
pp. 2639-2649 ◽  
Author(s):  
John P. Cherry ◽  
Clyde T. Young ◽  
Larry R. Beuchat
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Arachis Hypogaea ◽  
Free Amino Acids ◽  
Free Amino ◽  
Aspergillus Parasiticus ◽  
Amino Acid Content ◽  
Total Amino Acid ◽  
Sequence Of Events ◽  
Total Amino Acids

Protein and amino acid composition of peanuts (Arachis hypogaea L.) inoculated with Aspergillus parasiticus Speare were compared with those of non-infected seeds during an 18-day test period to determine metabolic changes within this interrelationship. The levels of buffer-soluble proteins of infected peanuts decreased rapidly to quantities much lower than those of non-infected seeds shortly after inoculation. Simultaneously, the levels of insoluble proteins increased to quantities greater than those contained in soluble fractions. Gel electrophoresis of soluble extracts from inoculated peanuts showed that proteins were hydrolyzed to many small-molecular-weight components, which eventually disappeared as fungal growth progressed. A corresponding increase in quantity of most free amino acids was observed shortly after inoculation of the peanuts. Major changes in free amino acid content coincided with substantial alterations of proteins in both soluble and insoluble fractions. These data suggested that inoculation of peanuts with A. parasiticus initiated a sequence of events whereby proteins were hydrolyzed first to small polypeptides and (or) insoluble components, then to free amino acids. After extended periods of infection, levels of free amino acids varied from day to day, suggesting that differential utilization of these components by the fungus was occurring. Quantities of total amino acids in whole seeds and soluble and insoluble fractions were different for non-inoculated and inoculated peanuts. Distinct differences were especially notable among samples of these three fractions of inoculated seeds. Differences in total amino acid contents apparently reflect qualitative and quantitative changes in proteins and (or) polypeptides present in various fractions examined during the infection period.

Amino acids of Diclidophora merlangi (Monogenea)

Parasitology ◽  
1975 ◽  
Vol 70 (1) ◽  
pp. 39-46 ◽  
Author(s):  
C. Arme ◽  
A. Whyte
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Free Amino ◽  
Dry Weight ◽  
Pool Analysis ◽  
Single Amino Acid ◽  
Parasite Protein ◽  
Total Pool ◽  
Host Blood

The level of free amino acids in Diclidophora merlangi is high, comprising over 500 μmoles/g ethanol extracted dry weight. A single amino acid, proline, constitutes some 70% of the total pool. Analysis of parasite protein and host blood and mucus revealed low proline levels, suggesting that the high free pool content was not related to a requirement for protein synthesis or to its abundance in the diet of the worm. Experiments revealed that proline was not involved specifically in osmoregulation, and the reasons for the large amounts present in Diclidophora remain unknown.

scholarly journals Sulfur Deficiency Influences Vegetative Growth, Chlorophyll and Element Concentrations, and Amino Acids of Pecan

1991 ◽  
Vol 116 (6) ◽  
pp. 974-980 ◽  
Author(s):  
Hening Hu ◽  
Darrell Sparks ◽  
John J. Evans
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Vegetative Growth ◽  
Free Amino ◽  
Chlorophyll Concentration ◽  
Dry Weight ◽  
Sulfur Deficiency ◽  
Protein Amino Acid ◽  
Deficiency Symptoms ◽  
S Deficiency

Greenhouse-grown pecan [Carya illinoensis (Wangenh.) C. Koch] seedlings were treated with S as SO4-2 (0 to 4 mm) to determine the effect of S on its vegetative growth, chlorophyll concentration, nutrition, and free and protein amino acid content. Sulfur deficiency symptoms occurred when leaf S was ≈1.5 mg·g-1 dry weight or less. Chlorophyll concentration and growth increased curvilinearly with leaf S and had not peaked when leaf S was 2.7 mg·g-1 dry weight. The N : S ratio in the leaf and leaf S were equally reliable indicators of the S status of the plant, but the optimum ratio was less than the value of 15 found in other plant species. Calcium and Mg decreased with S application, suggesting a direct SO4-2 or NH4+ effect. The concentration of all other elements determined was elevated, in one or more plant parts, when S deficiency symptoms were visible. The most conspicuous effect of S deficiency on N metabolism was a greatly expanded free amino acid pool, mainly arginine. The concentration of free amino acids decreased exponentially with leaf S. Conversely, protein amino acid was inhibited by S deficiency and increased with leaf S concentration or, perhaps more specifically, with methiouine.

scholarly journals Relationships of Nitrogenous Compounds in Petiole Sap of Tomato to Nitrogen Fertilization and the Value of these Compounds as a Predictor of Yield

HortScience ◽  
1999 ◽  
Vol 34 (2) ◽  
pp. 254-258 ◽  
Author(s):  
Peter C. Andersen ◽  
Fred M. Rhoads ◽  
Steven M. Olson ◽  
Brent V. Brodbeck
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Fertilization Rate ◽  
N Fertilization ◽  
Fruit Yield ◽  
Marketable Yield ◽  
Total N ◽  
Petiole Sap ◽  
Total Amino Acids

`Colonial' tomato (Lycopersicon esculentum Mill.) plants were grown on raised beds with black polyethylene mulch, drip irrigation, and preplant-N rates of 0, 67, 134, 202, or 269 kg·ha-1. Petiole sap was collected 7 and 13 weeks after transplanting. Concentrations of NO3-N, free amino acids, total amino acids, and total-N (the sum of NO3-N and amino acid-N) were examined as functions of the rate of N fertilization. Also, each of these compounds was used as an independent variable as a predictor of fruit yield. Seven weeks after planting, the concentrations of NO3-N and 15 of 18 of the free amino acids were correlated with the rate of N fertilization, but concentrations of bound or total amino acids were not. The amount of NO3-N accounted for 37% of the total-N in the 0 kg·ha-1 treatment, and up to 83% in the 202 kg·ha-1 treatment. NO3-N was highly correlated with total-N for both nonhydrolyzed and hydrolyzed sap (R2 = 0.98). Thirteen weeks after transplanting, neither the concentration of NO3-N nor that of amino acids, other than asparagine, glutamine, and proline, were significantly related to the rate of N fertilization. On both dates, concentrations of glutamine plus glutamic acid were correlated with rate of N fertilization whether expressed as absolute values or as percentage values. N fertilization rate and the concentration of NO3-N or total-N were related to total fruit yield (R2 = 0.69 to 0.74), and marketable fruit yield (R2 = 0.78 to 0.82). N-fertilization rate and petiole sap concentrations of NO3-N or total-N were also correlated with the N contained in total or marketable yield. Petiole sap variables measured 13 weeks after transplanting were not significantly correlated with fruit yield or the quantity of N contained in the fruit. Free, bound, or total amino acids in petiole sap were not as well correlated with fruit yield parameters as were N-fertilization rate, NO3-N, or total-N in petiole sap.

Biliary catabolism of glutathione and differential reabsorption of its amino acid constituents

1988 ◽  
Vol 254 (1) ◽  
pp. G1-G7 ◽  
Author(s):  
N. Ballatori ◽  
R. Jacob ◽  
C. Barrett ◽  
J. L. Boyer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Guinea Pigs ◽  
Free Amino Acids ◽  
Free Amino ◽  
Biliary Tree ◽  
Irreversible Inhibitor ◽  
High Degree ◽  
Bile Samples ◽  
Total Amino Acids

Biliary excretion of glutathione, free amino acids, and total amino acids (after acid hydrolysis) was measured in hepatic bile collected from guinea pigs, rabbits, and dogs anesthetized with pentobarbital sodium. In controls, the concentration of glutathione in bile was less than 20 microM in all three species. However, when hepatic gamma-glutamyltransferase activity was decreased by retrograde intrabiliary infusion of the irreversible inhibitor acivicin (AT-125; 20 mumol/kg), there was a marked increase in biliary glutathione excretion (in mumol glutathione equivalents.kg body wt-1.h-1) from 0.10 +/- 0.04 to 2.2 +/- 0.6 in guinea pigs, from 0.014 +/- 0.013 to 2.5 +/- 1.9 in rabbits, and from an undetectable level (less than 0.001) to 0.11 +/- 0.05 in dogs. Amino acid analysis of bile revealed that the concentration of glutathione's constituent amino acids (free glutamate, cystine, and glycine) in control bile samples from these three species were quite low and were not affected by AT-125. However, acid hydrolyzates of these same bile samples revealed an unusually high degree of amino acid conjugation. Glutamate (0.06-0.5 mM), cystine (0.2-1.1 mM), and glycine (1.7-2.8 mM) constituted the overwhelming majority of total amino acids in hydrolyzed bile from controls. After AT-125, concentrations of total glutamate and cystine were elevated in hydrolyzed bile, while concentrations of all other amino acids remained the same. Thus glutathione is avidly secreted into bile in the guinea pig, rabbit, and dog but is almost quantitatively broken down within the biliary tree. Subsequently, the glutamate and cysteine moieties derived from catabolism of glutathione must be partially reabsorbed either as peptides, conjugates, or free amino acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Sign in / Sign up

Export Citation Format

Share Document