PATHWAYS LEADING TO THE FORMATION OF AMINO ACIDS AND AMIDES IN LEAVES

1963 ◽  
Vol 41 (12) ◽  
pp. 1623-1638 ◽  
Author(s):  
R. G. S. Bidwell
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Krebs Cycle ◽  
Labelling Pattern ◽  
New Technique ◽  
Succinic Semialdehyde ◽  
A New Technique ◽  
Wheat Leaves ◽  
Krebs Cycle Intermediates

C14-labelled substrates were supplied to leaves, and the labelling patterns in derived amino acids were examined. A new technique is described for the ninhydrin decarboxylation of amino acids separated on paper chromatograms, making use of the Dynacon electrometer. Succinate-1,4-C14, succinate-2,3-C14, pyruvate-1-C14, pyruvate-2-C14, pyruvate-3-C14, C14O2, and glutamate-1-C14 were supplied to wheat leaves, and the total C14 and carboxyl-C14 in alanine, aspartate, glutamate, asparagine, and glutamine were determined. The results indicated that the amino acids and amides were formed mainly from the corresponding Krebs cycle intermediates. Carbon entered the Krebs cycle mainly by decarboxylation of pyruvate, but partly by its carboxylation. Extensive cycling did not occur. Various other suggested pathways, including the conversion of succinate to glutamic acid via succinic semialdehyde and γ-aminobutyrate followed by carboxylation, did not occur.When glucose-UL-C14 was supplied to pea or bean seedlings, the labelling pattern in alanine and glutamine indicated their derivation from glucose via glycolysis and Krebs cycle pathways. However, the pattern in asparagine indicated that it may have been formed from products of glyoxalate cycle.

Response of Hard Red Winter Wheat to Soilborne wheat mosaic virus Using Novel Inoculation Methods

2002 ◽  
Vol 92 (4) ◽  
pp. 347-354 ◽  
Author(s):  
Barbara A. Driskel ◽  
Robert M. Hunger ◽  
Mark E. Payton ◽  
Jeanmarie Verchot-Lubicz
Keyword(s):  
Mosaic Virus ◽  
Virus Resistance ◽  
Resistance Mechanisms ◽  
New Technique ◽  
Infested Soil ◽  
Wheat Cultivars ◽  
Inoculation Techniques ◽  
Hard Red Winter Wheat ◽  
A New Technique ◽  
Wheat Leaves

Soilborne wheat mosaic virus (SBWMV) is an agronomically important pathogen of wheat that is transmitted by the soilborne plasmodiophorid vector Polymyxa graminis. In the laboratory, attempts to generate SBWMV-infected plants are often hampered by poor infectivity of the virus. To analyze the mechanism for virus resistance in wheat cultivars, we developed novel inoculation techniques. A new technique for foliar inoculation of SBWMV was developed that eliminated wound-induced necrosis normally associated with rub inoculating virus to wheat leaves. This new technique is important because we can now uniformly inoculate plants in the laboratory for studies of host resistance mechanisms in the inoculated leaf. Additionally, wheat plants were grown hydroponically in seed germination pouches and their roots were inoculated with SBWMV either by placing P. graminis-infested root material in the pouch or by mechanically inoculating the roots with purified virus. The susceptibility of one SBWMV susceptible and three field resistant wheat cultivars were analyzed following inoculation of plants using these novel inoculation techniques or the conventional inoculation technique of growing plants in P. graminis-infested soil. The results presented in this study suggest that virus resistance in wheat likely functions in the roots to block virus infection.

scholarly journals NAC-NOR mutations in tomato Penjar accessions attenuate multiple metabolic processes and prolong the fruit shelf life

2017 ◽  
Author(s):  
Rakesh Kumar ◽  
Vajir Tamboli ◽  
Rameshwar Sharma ◽  
Yellamaraju Sreelakshmi
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Shelf Life ◽  
Krebs Cycle ◽  
Metabolic Processes ◽  
Cell Wall Modification ◽  
Metabolic Basis ◽  
Fruit Shelf Life ◽  
Krebs Cycle Intermediates ◽  
Reduced Water

AbstractSeveral Penjar accessions of tomato (Solanum lycopersicum), widely grown in the Mediterranean region, exhibit prolonged shelf life, and harbor alcobaca mutation with valine-106-aspartic acid substitution in the NAC-NOR protein. To uncover the metabolic basis underlying the prolonged shelf life, we compared four Penjar accessions to Ailsa Craig (AC). Three accessions bore alcobaca mutation, whereas fourth was a novel NAC-NOR allele with only six amino acids in the encoded protein. The cuticle composition among Penjars varied widely during the progression of fruit ripening. All Penjars exhibited delayed ripening, prolonged on-vine and off-vine shelf life, low ethylene emission and carotenoid levels albeit with accession-specific differences. Metabolic profiling revealed shifts in Krebs cycle intermediates, amino acids, and β-aminobutyric acid levels indicating the attenuation of respiration in Penjars during post-harvest storage. The prolonged shelf life of Penjar fruits was associated with a concerted downregulation of a number of cell-wall modifying genes and cell-wall-related metabolites. The accumulation of higher ABA and sucrose levels at the onset of senescence in Penjar fruits likely contribute to reduced water loss. Our analyses reveal that in addition to specialized cuticle composition, the attenuation of various metabolic processes by NAC-NOR mutation likely prolongs the shelf life of Penjar fruits.HighlightThe prolonged shelf life of tomato Penjar accessions bearing mutations in NAC-NOR transcription factor appears to be regulated by a combined effect of attenuation of respiration, altered cuticle composition, enhanced ABA and sucrose levels in fruits and downregulation of cell wall modification

The effect of thiourea and formaldehyde treatment on the chemical analysis of wool. II. Amino acid analyses

1970 ◽  
Vol 23 (3) ◽  
pp. 533 ◽  
Author(s):  
PW Nicholls ◽  
LC Gruen
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chemical Analysis ◽  
Acid Hydrolysis ◽  
New Technique ◽  
Formaldehyde Treatment ◽  
A New Technique

The anomalous amino acid analyses obtained for some amino acids, from the hydrolysates of thiourea-formaldehyde and formaldehyde-treated wool samples, are due largely to reactions with formaldehyde during acid hydrolysis. A new technique has been developed, involving hydrolysis in refluxing hydrochlorio acid in an atmosphere of nitrogen. This method improves the recovery of amino acids and has also been of assistance in explaining the abnormal analyses observed for oystine, tyrosine, lysine, and threonine in the presence of formaldehyde.

SOURCES OF CARBON FOR THE SYNTHESIS OF PROTEIN AMINO ACIDS IN ATTACHED PHOTOSYNTHESIZING WHEAT LEAVES

1963 ◽  
Vol 41 (7) ◽  
pp. 985-994 ◽  
Author(s):  
J. A. Hellebust ◽  
R. G. S. Bidwell
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Protein Turnover ◽  
Soluble Sugars ◽  
Protein Nitrogen ◽  
Considerable Portion ◽  
Protein Amino Acids ◽  
Specific Activities ◽  
Wheat Leaves

Attached, rapidly growing wheat leaves were allowed to photoassimilate C14O2 and C12O2 alternately. Samples of leaves were collected after each period of photosynthesis and were analyzed for amounts and total activities of soluble sugars and amino acids, and protein amino acids. The leaves were also analyzed for protein nitrogen and amounts and total activities of respired carbon. Samples of roots were also collected and the amounts, total activities, and specific activities of their soluble compounds were determined. It was possible to calculate from these data the proportions of carbon entering some protein amino acids which came either from soluble amino acid pools or by a direct route from photosynthate, bypassing the soluble pools. More than half of the carbon entering protein-bound serine and glycine was derived from newly assimilated CO2, while protein glutamic acid, aspartic acid, and alanine derived more of their carbon from the soluble amino acid pools. Analysis of the data from roots indicated that a considerable portion of the carbon translocated from the leaves was derived from newly assimilated CO2. There was some indication that protein turnover took place, but it was concluded that proteins could not have contributed significantly as substrates for respiration in these leaves.

Metabolism of [U-14C]D-fructose by the isolated perfused udder

1969 ◽  
Vol 36 (2) ◽  
pp. 233-239 ◽  
Author(s):  
R. Verbeke ◽  
Anne-Marie Massart-Leën ◽  
G. Peeters
Keyword(s):  
Amino Acids ◽  
Mammary Gland ◽  
Citric Acid ◽  
Glutamic Acid ◽  
Krebs Cycle ◽  
Casein Hydrolysate ◽  
Relative Distribution ◽  
Limited Extent ◽  
Lactating Mammary Gland ◽  
Specific Activities

SummaryA lactating mammary gland of a sheep and a goat were perfused for several hours in the presence of [U-14C]D-fructose and received adequate quantities of acetate, glucose and amino acids.In both experiments, there was a small incorporation of 14C in the expired CO2. Smaller radioactivities were measured in milk citric acid, lactose, casein and fat, the activities decreasing in that order. The specific activities of the amino acids from one casein hydrolysate were determined. The highest radioactivities were found in alanine and serine; methionine, glutamic acid and aspartic acid showed a smaller incorporation of 14C.These results indicate that fructose is metabolized only to a very limited extent by the mammary gland. The relative distribution of 14C observed among the different substances isolated may be explained by a direct splitting of fructose into two C3-fragments, glycolysis and metabolism via the Krebs cycle.

Enzyme immunoassay--a new technique for estimating hemoglobin A1c

1993 ◽  
Vol 39 (4) ◽  
pp. 663-666 ◽  
Author(s):  
W G John ◽  
M R Gray ◽  
D L Bates ◽  
J L Beacham
Keyword(s):  
Amino Acids ◽  
Enzyme Immunoassay ◽  
Hemoglobin A1c ◽  
Reference Interval ◽  
Microtiter Plate ◽  
New Technique ◽  
Beta Chain ◽  
Amadori Product ◽  
Different Types ◽  
A New Technique

Abstract We describe a method for estimating hemoglobin A1c (HbA1c) with a commercially available enzyme immunoassay system. The method is based on microtiter plate technology, utilizing an antibody raised to hemoglobin, the epitope being the Amadori product of glucose plus the first eight amino acids on the N-terminal end of the beta chain of hemoglobin. The enzyme immunoassay displays good within-batch (CV 2.3-2.4%) and between-batch (CV 2.6-5.0%) precision, and the results were not affected by different types of anticoagulant. The method was linear within the expected range of results and showed good correlation (r = 0.88-0.98) with established methods for estimating glycohemoglobin. Using this method, we obtained a reference interval of 2.8-4.9% (central 95%) for HbA1c in a nondiabetic population. The percentages of hemoglobin that were HbA1c in diabetics (6.86% +/- 2.51%) were significantly greater (P < 0.001) than in nondiabetics (3.46% +/- 0.52%).

EFFECT OF RUST-INHIBITING COMPOUNDS ON THE METABOLISM OF WHEAT LEAVES

1961 ◽  
Vol 39 (5) ◽  
pp. 1019-1027 ◽  
Author(s):  
D. J. Samborski ◽  
R. Rohringer ◽  
Clayton Person
Keyword(s):  
Amino Acids ◽  
Nucleic Acids ◽  
Glutamic Acid ◽  
Rust Fungus ◽  
Puccinia Recondita ◽  
In Vivo Metabolism ◽  
Quantitative Analyses ◽  
Wheat Leaves ◽  
Lower Recovery

Healthy leaves of Little Club wheat (Triticum compactum Host.) and leaves infected by leaf rust (Puccinia recondita Rob. ex. Desm. race 5) were detached and floated for 3 days on solutions containing 10 p.p.m. canavanine, 0.1% azathymine, 0.125% dulcitol, and 0.1% methionine. Leaf samples were fed with uniformly labelled glucose for 24 hours, fractionated, and the C14-content of each fraction was determined. Compared with controls, canavanine slightly reduced the amount of C14in amino acids, nucleic acids, and proteins while 6-azathymine markedly reduced the amount of C14in nucleic acids and proteins. Treatment with dulcitol resulted in a lower recovery of C14from all fractions other than sugars while methionine had little effect on the distribution of C14from glucose. Quantitative analyses showed a marked increase in amino acids after canavanine, 6-azathymine, and methionine treatments and a reduced level of nucleic acids after treatment with canavanine and azathymine.Canavanine had no effect on the incorporation of arginine and glutamic acid into leaf proteins while 6-azathymine inhibited the incorporation of adenine into nucleic acids. It was not possible to relate the changes that occurred following these treatments to the in vivo metabolism of the rust fungus.

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