Acid In Wheat Research Articles

Protein and free amino acids in wheat grain as affected by soil types and salinity levels in irrigation water

The effects of four lysimeter soil series under three salinity levels were evaluated for grain yield, wt/1000 seeds, protein, and amino acids in Mexican dwarf wheat (Triticum aestivum L. var. Cajeme 71). The soil series consisted of: Holtville clay loam, Greenfield sandy loam, San Emigdio sandy loam, and Altamont clay loam. The irrigation water salinity levels were designated: low −2.2 mmho, medium −4.2 mmho, and high −7.1 mmho.

Effect of content and distribution of hydroxamic acids in wheat on infestation by the aphid Schizaphis graminum

The content of hydroxamic acids in wheat plants shows substantial variations between different species and cultivars (1.0–6.3 mmol/kg fr. wt). It also varies with the age of the plant and the organ assayed. The maximum concentration is reached by the fourth day in epicotyls and roots. The amount in leaves at different plant ages is always higher in the younger leaves. Based on feeding and infestation experiments, it is proposed that the distribution of aphids on leaves of different ages is regulated by the hydroxamic acid content.

Specific ion effect on the accumulation of abscisic acid in wheat

Abstract Studies were carried out in the glass house using sand culture to find out the specific ion effect on the accumulation of abscisic acid in wheat. Seeds were sown in sixteen different solutions of chloride, sulphate, nitrate, carbonate salts of sodium, potassium, calcium and magnesium used each at ‐2 bar osmotic potential. The leaf samples taken after 25 days of sowing indicated that osmotic as well as salt stress increased significantly the accumulation of abscisic acid. The accumulation of abscisic acid was significantly less under potassium and calcium salt ions as compared to that under sodium and magnesium salts ions. Overall effect of anions showed that accumulation of abscisic acid was more under PEG (osmotic stress and chloride salts but it was less under sulphate and nitrate salts and was the least under carbonate salts. The accumulation of abscisic acid was exceptionally high under potassium dihydrogen phosphate. In general, the accumulation of abscisic acid‐a growth inhibitor varied not...

Assessment of the nutritional quality of proteins: the use of "ileal" digestibilities of amino acids as measures of their availabilities.

1. A comparative study was made of two biological techniques for assessing protein quality in wheat and barley, and in a soya-bean-protein isolate both as received, and after being heat damaged by autoclaving. Amino acid digestibility was determined by the "ileal" analysis technique while amino acid availability was measured in growth assays. Some chemical and microbiological tests were also done. 2. Heat treatment of the soya-bean-protein isolate caused little change in amino acid composition but the digestibility of all amino acids and the availability of lysine and methionine were severely reduced, lysine being most affected. The reduced availability of lsyine was not entirely attributable to impaired digestibility. 3. The amino acids in wheat and barley were highly digestible. The availability of methionine and lysine in barley and of methionine in wheat was high, whereas the availability of lysine in wheat was apparently much lower. 4. The results showed that for methionine, digestibility values are a fair measure of the availability. In heat-damaged soya-bean-protein isolate however, digestibility of lysine over-estimated the availability, indicating that amino acid digestibility may sometimes provide a misleading indication of nutritional value.

Effects of nitrogen, phosphorus and potassium on amino acid composition and on relationships between nitrogen and amino acids in wheat and oat grain

AbstractDuring two seasons, pot experiments in which increasing applications of nitrogen, phosphorus and potassium were given to wheat and oats produced grain with widely varying N contents. The total amino acid composition of the grain was mainly dependent on N content of grain. Phosphorus and potassium affected the amino acid composition of wheat and oat grain only indirectly through their effects on nitrogen concentration. In wheat increasing grain N% was accompanied by a decrease in the amount (as g per 16 g N) of lysine, threonine, methionine, cystine and an increase in glutamic acid, proline, phenylalanine, and serine contents. Lysine, methionine, and cystine in oats decreased with increasing grain N content, but arginine, aspartic acid, glutamic acid and phenylalanine increased. Changes were less pronounced with oats than with wheat, and concentrations of most essential amino acids were higher in oats. When expressed as % dry matter all amino acids increased with increasing N concentration. Linear regression equations were calculated and significant correlations were found in both crops between concentrations of most amino acids and N content in grain. Some correlations between amino acids in the grain are also given. Correlations between amino acids and nitrogen within a variety were similar despite widely differing yields.

SELENIUM TOXICITY IN PLANTS AND ITS DETOXICATION BY PHOSPHORUS

Selenium toxicity and the effect of P application on Se in wheat (Triticum aestivum) was studied in a greenhouse experiment using the sandy soil of Haryana Agricultural University, Hissar, India. Selenium was applied at 0, 2.5, 5, and 10 ppm as Na2SeO3–5H2O, and P at 0, 50, and 100 ppm as KH2PO4. The application of P at 50 ppm increased, and that at 100 ppm decreased, dry matter, grain yield, N, S, Zn, Cu, chlorophyll, DNA, RNA, protein, and proline contents, and S-amino acids in wheat. Contents of Fe and Mn decreased as P increased to 50 and 100 ppm. Plant P increased with increases in added P up to 100 ppm. In P control and 50 ppm P treatments, the addition of Se decreased dry matter yield, grain yield, N, Zn, Cu at 50 days and maturity (135 days), DNA, RNA, protein, and proline in plants at 45 and 90 days after planting, and S-amino acids in grains, but 2.5 ppm Se with 50 ppm P increased, P, S, Fe, and Mn, and 2.5 and 5 ppm Se with 100 ppm P were beneficial on almost all parameters. Se content increased with 50 ppm P and all concentrations of Se, but decreased with 100 ppm P. Free amino acids were greater at 90 days than at 45 days sampling. Phosphorus application decreased free amino acids, but Se increased them. Sunflower (Helianthus annuus) was grown after wheat to see the residual effect of Se and P. In sunflower there was low accumulation of Se, which increased with high Se and 50 ppm P, and decreased with 100 ppm P applied to the wheat crop. But, in this case, 50 and 100 ppm P added to the wheat crop increased N, P, and S. At 100 ppm P added to wheat, 2.5 and 5 ppm Se showed increased dry matter, P, and S content at 90 and 135 days. The high amounts (2.5 ppm and above) of added and residual Se in soil decreased the growth of wheat and sunflower, the absorption of Zn, Cu, Fe, Mn, S, and N, and the synthesis of nucleic acids, chlorophyll, and protein, whereas P decreased the harmful effect of Se, and increased all the above parameters.

Aspartate kinase and the synthesis of aspartate-derived amino acids in wheat

Aspartate kinase (EC 2.7.2.4.) has been purified from 7 day etiolated wheat (Triticum aestivum L. var. Maris Freeman) seedlings and from embryos imbibed for 8 h. The enzyme was 50% inhibited by 0.25 mM lysine. In this study wheat aspartate kinase was not inhibited by threonine alone or cooperatively with lysine; these results contrast with those published previously. In vivo regulation of the synthesis of aspartate-derived amino acids was examined by feeding [(14)C]acetate and [(35)S]sulphate to 2-3 day germinating wheat embryos in culture in the presence of exogenous amino acids. Lysine (1 mM) inhibited lysine synthesis by 86%. Threonine (1 mM) inhibited threonine synthesis by 79%. Lysine (1 mM) plus threonine (1 mM) inhibited threonine synthesis by 97%. Methionine synthesis was relatively unaffected by these amino acids, suggesting that there are important regulatory sites other than aspartate kinase and homoserine dehydrogenase. [(35)S]sulphate incorporation into methionine was inhibited 50% by lysine (2 mM) plus threonine (2 mM) correlating with the reported 50% inhibition of growth by these amino acids in this system. The synergistic inhibition of growth, methionine synthesis and threonine synthesis by lysine plus threonine is discussed in terms of lysine inhibition of aspartate kinase and threonine inhibition of homoserine dehydrogenase.

Nutritional evaluation of wheat. 5. Disappearance of components in digesta of pigs prepared with two re-entrant cannulae

SUMMARY1. Three pigs prepared with re-entrant cannulae in the proximal duodenum and terminal ileum were used to study flow rate of nitrogen, and digestion and absorption of dry matter, nitrogen, gross energy and starch. The pigs were given a semi-purified diet, a hard wheat diet and a soft wheat diet. These were approximately isonitrogenous.2. Nitrogen content of insoluble dry matter of duodenal digesta was much higher on the semi-purified diet than on the wheat-based diets.3. Apparent digestibilities of dry matter, energy and nitrogen in the small intestine were in the order semi-purified diet > hard wheat > soft wheat although differences were not statistically significant. Similar results were obtained for total digestibility of these components.4. Absorption of most amino acids from the small intestine was higher for casein in the semi-purified diet than for wheat protein. Significantly more lysine, arginine, isoleucine and tyrosine were absorbed from hard than from soft wheat.5. With all diets there was almost complete digestion of starch in the small intestine.6. There was little digestion of nutrients in the large intestine, and thus digestibilities calculated from faecal analyses showed similar trends to those calculated from analyses of digesta from the terminal ileum. Most values compared favourably with those reported elsewhere for digestibilities of amino acids in wheat.7. It was concluded that casein was superior to the wheat proteins but that protein of hard wheat was of better quality than that of soft wheat when evaluated by ileal recovery of animo acids, due largely to a greater absorption of lysine.

Phenolic acids in wheat and paddy rhizosphere amended with crop residue

Phenolic acids in the rhizosphere soil of wheat and paddy crops, amended with straw alone and straw in conjunction with nitrogen before 45, 30 and 0 days of sowing the crops were estimated by paper chromatography. Catechol,p-hydroxybenzoic,p-coumaric and vanillic acids were common to the rhizosphere of both the crops irrespective of straw and nitrogen treatments. Slightly high quantities ofp-hydroxy benzoic acid and catechol were encountered in wheat rhizosphere whereas in paddy rhizospherep-coumaric acid and catechol were more compared to other acids. Larger number of acids were encountered in wheat rhizosphere soil than paddy. Straw and nitrogen amendments appeared to have little effect on phenolic acid content in rhizosphere soil of both the crops.

Amino Acid Content in Wild Rice (Zizania Aquatica L.) Grain1

AbstractWild rice (Zizania aquatica L.), until recently only harvested from natural stands, is now being cultivated in the upper‐midwestern U.S. and southern Canada. Thus, it is becoming a more common food. The objective was to determine the amino acid composition of the protein in wild rice grain.The content of 17 amino acids and protein percentage of five grain samples of wild rice grown in Minnesota were determined and compared to hard red spring wheat (Friticum aestivum L. em. Thell.) and spring oat groats (Avena sativa L.).The wild rice grain tested had nearly twice the percentage of the amino acids alanine, arginine, aspartic, lysine, and methionine than wheat grain. Wheat grain had about twice the percentage of cystine, glutamic acid, and proline amino acids as wild rice grain. The nine essential amino acids tested comprised 32.1 and 45.1% of the total amino acids in wheat and wild rice grain, respectively. The protein percentage was 17.1 for wheat grain and 14.2 for wild rice grain.Generally the percentages of amino acids tested were similar for wild rice grain and oat groats except for slightly higher percentages of alanine, arginine, aspartic, and methionine in wild rice grain. Oat grain had higher percentages of cystine and glutamic acid than wild rice grain. The nine essential amino acids tested comprised 42.0 aml 45.1% of the total amino acids in oat groats and wild rice grain, respectively. The protein percentage in eat groats was 16.5% compared to 14.2% in wild rice grain.

Evaluation Of A High Performance Liquid Chromolography (Hplc) Mehtod For Amino Acid Analysis In Feed With Precolumn Derivatization And Fluorescence Detection

An experiment was conducted to determine the amino acids content in wheat sample which is often used as internal check in animal feed analysis by pre-column derivatization method using ortho-phthaldialdehyde (OPA) and betamercaptoethanol followed by high-performance liquid chromatography (HPLC). Fluorescence detection was used for the assay of OPA derivatives of amino acids with the detection wavelength set at Ex 340 nm and Em 455 nm. Ortho-phthaldialdehyde reagent itself does not fluorescence and hence produces no peak on the chromatogram and also produces a very low level of background noise. From standard amino acid mixture fourteen amino acids (Asp, Glu, Ser, Gly, Thr, Arg, Ala, Tyr, Met, Val, Phe, Ile, Leu, and Lys) were separated in 55 min with fine resolution. Good reproducibility and accuracy of the method were demonstrated by the determination of amino acids in wheat sample. The precision for the retention time of amino acids (n = 10 injections over 3 days) between the days showed average standard deviation (SD) of 0.43 and coefficient of variation (CV) of 3.32%. The average SD and CV of peak area repeatability over n = 10 injections were 0.72 and 14.93% also indicated the higher sensitivity of the method. The results of the amino acids in wheat samples suggested that the method can be potentially applied for the determination of amino acids in wheat as well as other cereal feeds used in animal diets. DOI: http://dx.doi.org/10.3329/bjas.v37i2.9883 BJAS 2008; 37(2): 66-73

Salt stress mitigation by salicylic acid in wheat for food security in coastal area of Bangladesh

Salt stress has a large impact on controlling the plant growth and development. The present study was conducted to examine the role of salicylic acid on alleviation of salt stress in wheat. In this experiment, the treatment consisted of four different salinity levels viz. S0 = without salt (control), S1 = 2.8 g NaCl kg-1 soil ? 3-4 dSm-1, S2 = 6.0 g NaCl kg-1 soil ? 7-8 dSm-1, S3 = 9.0 g NaCl kg-1 soil ? 11-12 dSm-1 and three different levels of salicylic acid (SA) viz. A0 = 0 mM, A1= 0.2 mM and A2 = 0.4 mM. It was done by using two factors Randomized Complete Block Design (RCBD) with four replications. The total treatment combinations were 12 (4x3). Results of the experiment showed a significant dissimilarity among the treatments in respect of the major parameters. Yield of wheat were exaggerated by different levels of salinity. The higher levels of salinity showed greater reduction of yield. The highest grain yields (1.55 tha-1) were recorded at S0A2 (Without Salt + 0.4 mM salicylic acid) treatment combination which did not show any difference with S0A0 (Without Salt+ Without SA) and S0A1 (Without Salt + 0.2 mM SA). But the grain yield was gradually decreased with the increasing level of salinity. The application of salicylic acid increased the grain yield differently according to the levels of salinity. The minimum grain yields were found 1.14 t ha-1, 1.07 tha-1 and 0.26 t ha-1 at 3-4 dSm-1, 7-8 dSm-1 and 11-12 dSm-1 NaCl respectively. These yields were increased with SA (0.4 mM) from 1.14 to 1.32 tha-1, 1.07 to 1.14 tha-1 and 0.26 to 0.31 tha-1 at 3-4 dSm-1, 7-8 dSm-1 and 11-12 dSm-1 NaCl respectively. These results suggest that salicylic acid can alleviate the detrimental impacts of salinity and increase the grain yield of wheat.

METABOLISM OF AROMATIC COMPOUNDS IN HEALTHY AND RUST-INFECTED PRIMARY LEAVES OF WHEAT: I. STUDIES WITH14CO2, QUINATE-U-14C, AND SHIKIMATE-U-14C AS PRECURSORS

Healthy and stem rust infected leaves of two near-isogenic lines of wheat were allowed to metabolize14CO2, quinate-U-14C, or shikimate-U-14C for 22 h in the light.Quinate-U-14C and shikimate-U-14C were interconvertible but differed in their efficiency as precursors of phenylalanine and tyrosine, suggesting that an alternative pathway, not via shikimate, exists from quinate to phenylalanine in wheat leaves. Activity from the cyclites was not incorporated into tryptophan during the metabolic period. Evidently, synthesis of aromatic amino acids in wheat leaves is not restricted to the "classic" shikimate pathway.Infection with rust led to an increase of the carbon How from CO2to shikimate and to higher levels of both quinate and shikimate. This trend was more pronounced in susceptible than in resistant leaves. Moreover, utilization of quinate and shikimate was increased in infected susceptible leaves but was not altered significantly in infected resistant leaves. Resistant and susceptible reacting leaves differed in the distribution of activity derived from quinate-U-14C and shikiniate-U-14C. With shikimate-U-14C as precursor, resistant reacting leaves accumulated activity in unidentified components of the amino acid fraction (Amberlite IR-120 eluate). Susceptible reacting leaves accumulated less activity in these compounds, and healthy leaves contained only traces of activity in them. When either quinate-U-14C or shikimate-U-14C was metabolized by healthy leaves, more activity was recovered in insoluble esters (of ferulate and p-coumarate) than in soluble esters. Resistant reacting leaves accumulated still more activity in the insoluble esters, whereas susceptible reacting leaves contained a proportionately higher amount of activity in soluble esters. Compared with healthy leaves, susceptible reacting leaves always contained less activity, and resistant reacting leaves more activity, in the non-hydrolyzable, insoluble residue.

CARBON METABOLISM OF C-14-LABELED AMINO ACIDS IN WHEAT LEAVES. 3. FURTHER STUDIES ON THE ROLE OF SERINE IN GLYCINE METABOLISM.

the conversion of glycine to serine in wheat leaves lroceeds rapidly in the light, but the reverse reaction l)roceeds very slowly. Because the carl)on atomlls of glyciine were utilized readily for the synithesis of sugars in the light, anid the rate of incorporation was greatly reduced in the dark (2), the following questionl arises: Does the metabolism of glycine and of serine follow the same sequences of reactions in the dark as in the light? The present report will present evidence that the glyoxylate-serine pathway is operative in wheat leaves in the dark, and that serine assumes a key role in the metabolism of glycine in the dark as it does in the light.

CARBON METABOLISM OF GLYCINE AND SERINE IN RELATION TO THE SYNTHESIS OF ORGANIC ACIDS AND A GUANINE DERIVATIVE.

The metabolism of glycine or serine in aninmals alnd niicroorganisms has been well documented. The catabolism of glycine by way of glyoxylate is by far the 1mnost imiiportalnt pathway in mammalian tissues (9,10) and in microorganisms (2). Glyoxylate could be formiied from glycine either by the action of glycine oxidase (14) or by transamination (8,11). The metabolic conversion of serine to glycine and a 1-carhon uinit is reversible and has been denmonstrated to occur in animals (5) and plants (6,7,20). lHowever, in wheat leaves, glycine is converted preferentially to serine (16,17). The conversion of serine to glycine in vivo in wheat leaves proceeds very slowly (16,17). Wang and Waygood (18) investigated the conversion of glycine to sugars in wheat leaves and proposed a glyoxylate-serine pathway in wvhich serine occupies a key position as an essenitial internmediate. Rabson et al. (13) also have discussed the glycolate pathway for the production of precursors of hexoses. Recently, the role of serine in glycinie metabolism has been clearly demonstrated by Wang and Burris (16,17), and glyceric acid has been implicated as an intermediate between serine and hexoses (13,16,17,18). In additioni to the transformation of glycine or serine to hexoses, a considerable portion of either amino acid is utilized for the synthesis of a number of acidic compounds (15-18). The type of compotunds derived fromii these amino acids, besides glyceric and glycolic acids, had not been investigated fully, and the present communication deals with some of the fin(dinigs fromii a study of these compotnll(s.

Studies on plant growth‐regulating substances. XX. The metabolism of γ‐(2,4,5‐trichlorophenoxy)butyric acid in wheat and pea stem tissues

SUMMARYGas chromatography has been used to study the capacity of wheat and pea stem tissues and growing seedlings to degrade the side chain of γ‐(2,4,5‐trichlorophenoxy)butyric acid. The substance was converted to its acetic derivative in wheat, presumably undergoing β‐oxidation within the tissues. No evidence for such breakdown was obtained in pea stems. The results are fully consistent with the earlier findings of Wain and Wightman who studied these same systems by other methods.

Nucleotide composition of ribonucleic acid of wheat leaves

Nucleotide composition of ribonucleic acid of wheat leaves

Carbon Metabolism of C14-Labeled Amino Acids in Wheat Leaves. II. Serine & its Role in Glycine Metabolism

Wang and Waygood (24) investigated the conversion of glycine to sugars in wheat leaves and proposed a glyoxylate-serine pathway in which serine occupies a key position as an essential intermediate. Rabson et al. (19) also have discussed the glycolate pathway for the production of precursors of hexoses. They have reviewed much of the literature on the metabolism by plants of glycolic acid, glyoxylic acid, glyceric acid, glycine, serine, and related intermediates. Glycolic acid is an early product of photosynthesis (1), and a substantial percentage of the total carbon of the photosynthetic cycle enters into glycolate (1,25). This was shown dramatically when Zelitch (27) blocked glycolate oxidation with an a-hydroxysulfonate and demonstrated that approximately half of the C14 fixed appeared in glycolic acid. Kearney and Tolbert (11) showed that C14-labeled glvcolate and phosphoglycolate appeared rapidly outside isolated chloroplasts photosynthesizing C1402, and they suggested that these compounds likely are of special importance in the transport of photosynthate between chloroplasts and cytoplasm. Glycine arises from glyoxylate and in turn serves as a precursor for serine. Rabson et al. (19) also have implicated glycerate as an intermediate between serine and hexoses, and have suggested that this glycerate formed by the glycolate pathway represents a precursor for hexoses independent of the phosphoglyceric acid formed from the carboxylation of ribulose diphosphate. In the present work, an attempt has been made to substantiate the role of serine in the metabolism of glycine as well as to investigate the glyoxylateserine pathway in general. Metabolic changes with time in a number of labeled substrates have been followed in an attempt to clarify the interrelationships between these simple organic acids and amino acids and their roles as precursors for sugar synthesis. Materials & Methods

The phenolic acids in wheat—III.: Insoluble derivatives of phenolic cinnamic acids as natural intermediates in lignin biosynthesis

14C-Labeled compounds were administered to wheat shoots and their incorporation into lignin and into p-coumaric, ferulic and sinapic acids was measured. These phenolic cinnamic acids were not present as such but were obtained by alkaline hydrolysis of both the ethanol extract and the insoluble residue. Measurement of the incorporation into lignin was based on alkaline nitrobenzene oxidation of the residue to vanillin, syringaldehyde and p-hydroxybenzaldehyde. Labeled carbon dioxide, phenylalanine or tyrosine was incorporated more readily into the phenolic cinnamic acids bound to the insoluble residue than into ethanol soluble derivatives whereas the reverse was true for labeled precursors such as cinnamic, p-coumaric, caffeic, ferulic, and sinapic acids. Time-course studies with labeled carbon dioxide suggested the sequence: carbon dioxide →aromatic amino acids→ethanol-insoluble derivatives of the phenolic cinnamic acids→lignin. Soluble derivatives of the phenolic cinnamic acids appear to exchange with the insoluble derivatives and to act as intermediates in lignification especially when the free acids are administered. A scheme is suggested to explain these complex relationships.

Carbon metabolism of C14-labeled amino acids in wheat leaves. I. A pathway of glyoxylate-serine metabolism

Carbon metabolism of C¹⁴-labeled amino acids in wheat leaves. I. A pathway of glyoxylate-serine metabolism