scholarly journals Short-term inhibition of glutamine synthetase leads to reprogramming of amino acid and lipid metabolism in roots and leaves of tea plant (Camellia sinensis L.)

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Mei-Ya Liu ◽  
Dandan Tang ◽  
Yuanzhi Shi ◽  
Lifeng Ma ◽  
Yan Li ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamine Synthetase ◽  
Tca Cycle ◽  
Tea Plant ◽  
Tea Leaves ◽  
Short Term ◽  
N Metabolism ◽  
Short Time ◽  
Related Compounds

Abstract Background Nitrogen (N) nutrition significantly affected metabolism and accumulation of quality-related compounds in tea plant (Camellia sinensis L.). Little is known about the physiological and molecular mechanisms underlying the effects of short-term repression of N metabolism on tea roots and leaves for a short time. Results In this study, we subjected tea plants to a specific inhibitor of glutamine synthetase (GS), methionine sulfoximine (MSX), for a short time (30 min) and investigated the effect of the inhibition of N metabolism on the transcriptome and metabolome of quality-related compounds. Our results showed that GS activities in tea roots and leaves were significantly inhibited upon MSX treatment, and both tissue types showed a sensitive metabolic response to GS inhibition. In tea leaves, the hydrolysis of theanine decreased with the increase in theanine and free ammonium content. The biosynthesis of all other amino acids was repressed, and the content of N-containing lipids declined, suggesting that short-term inhibition of GS reduces the level of N reutilization in tea leaves. Metabolites related to glycolysis and the tricarboxylic acid (TCA) cycle accumulated after GS repression, whereas the content of amino acids such as glycine, serine, isoleucine, threonine, leucine, and valine declined in the MXS treated group. We speculate that the biosynthesis of amino acids is affected by glycolysis and the TCA cycle in a feedback loop. Conclusions Overall, our data suggest that GS repression in tea plant leads to the reprogramming of amino acid and lipid metabolic pathways.

Effect of Intraduodenal Starch Infusion on Net Portal Absorption of Amino Acids in Growing steers Fed Lucerne

1994 ◽  
Vol 1994 ◽  
pp. 28-28
Author(s):  
C.J. Seal ◽  
D.S. Parker ◽  
J.C. MacRae ◽  
G.E. Lobley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gastrointestinal Tract ◽  
Protein Turnover ◽  
Portal Blood ◽  
Intestinal Lumen ◽  
Short Term ◽  
Net Uptake ◽  
Amino Acid Requirements ◽  
Glucose Availability

Amino acid requirements for energy metabolism and protein turnover within the gastrointestinal tract are substantial and may be met from luminal and arterial pools of amino acids. Several studies have demonstrated that the quantity of amino acids appearing in the portal blood does not balance apparent disappearance from the intestinal lumen and that changing diet or the availability of energy-yielding substrates to the gut tissues may influence the uptake of amino acids into the portal blood (Seal & Reynolds, 1993). For example, increased net absorption of amino acids was observed in animals receiving exogenous intraruminal propionate (Seal & Parker, 1991) and this was accompanied by changes in glucose utilisation by the gut tissues. In contrast, there was no apparent change in net uptake of [l-13C]-leucine into the portal vein of sheep receiving short term intraduodenal infusions of glucose (Piccioli Cappelli et al, 1993). This experiment was designed to further investigate the effects on amino acid absorption of changing glucose availability to the gut with short term (seven hours) or prolonged (three days) exposure to starch infused directly into the duodenum.

DETERMINATION OF PROTEIN SYNTHESIS IN RAINBOW TROUT, ONCORHYNCHUS MYKISS, USING A STABLE ISOTOPE

1994 ◽  
Vol 189 (1) ◽  
pp. 279-284
Author(s):  
C Carter ◽  
S Owen ◽  
Z He ◽  
P Watt ◽  
C Scrimgeour ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Rainbow Trout ◽  
Amino Acid ◽  
Oncorhynchus Mykiss ◽  
Considerable Proportion ◽  
Published Data ◽  
Short Term ◽  
Terrestrial Mammals ◽  
Rainbow Trout Oncorhynchus Mykiss

It has been suggested (Houlihan, 1991) that the consumption of 1 g of protein in a variety of species of fish stimulates the synthesis of, approximately, an equal amount of protein. Although synthesis of protein may account for as much as 40 % of the whole-animal oxygen consumption (Lyndon et al. 1992), only about 30 % of the synthesized proteins are retained as growth (Houlihan et al. 1988; Carter et al. 1993a,b). Thus, one focus of attention is the potential advantage gained by fish in allocating a considerable proportion of assimilated energy to protein turnover in contrast to relatively low-cost, low-turnover protein growth (Houlihan et al. 1993). Rates of protein synthesis in several species of fish have been measured using radioactively labelled amino acids, frequently given as a flooding dose (reviewed by Fauconneau, 1985; Houlihan, 1991). These measurements cannot be made for longer than a few hours because of the decline in specific radioactivity in the amino acid free pool. However, as protein synthesis rates vary during the course of a day as a result of the post-prandial stimulation, and since radiolabelled amino acid methodology is invasive, short-term and terminal, it has been difficult to be certain of the relationship between protein growth measured in the long term and protein synthesis rates measured in the short term. This paper addresses these problems by developing a method using 15N in orally administered protein to measure protein synthesis rates in fish over relatively long periods, the aim being to use procedures that are as non-invasive and repeatable as possible. The use of stable isotopes to measure protein metabolism is well established in terrestrial mammals (see Rennie et al. 1991; Wolfe, 1992), but to our knowledge the only published data for aquatic ectotherms are on the blue mussel (Mytilus edulis L.) (Hawkins, 1985). In the present study, rates of protein synthesis of individual rainbow trout [Oncorhynchus mykiss (Walbaum)] were calculated from the enrichment of excreted ammonia with 15N over the 48 h following the feeding of a single meal (dose) containing protein uniformly labelled with 15N by use of an end-point stochastic model (Waterlow et al. 1978; Wolfe, 1992). Application of this type of modelling would appear to be ideal for measuring ammonotelic fish nitrogen metabolism since, unlike the situation in mammals, the catabolic flux of amino acids through urea is very small. Further, ammonia is excreted directly into the surrounding water via the gills and is not stored for any length of time, in contrast to the situation in mammals, so the rate of tracer appearance is easily measurable.

Chelating polymers. I. The synthesis and acid dissociation behavior of several N-(p-vinylbenzenesulfonyl)-substituted diaminopolyacetic acid monomers, monomeric analogues, and related intermediates

1970 ◽  
Vol 48 (1) ◽  
pp. 163-175 ◽  
Author(s):  
R. M. Genik-Sas-Berezowsky ◽  
I. H. Spinner
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dissociation Constants ◽  
Acid Dissociation ◽  
Inductive Effects ◽  
Cyclic Amide ◽  
Amino Acid Analogues ◽  
Related Compounds ◽  
Chelating Polymers ◽  
Made In

Two new chelating monomers, N-(p-vinylbenzenesulfonyl)1,2-diaminoethane-N′,N′-diacetic (SS-EDDA) and -N,N′,N′-triacetic (SS-ED3A) acids, as well as several monomeric analogues and related intermediates have been prepared. In addition, 2-oxo-1-piperazine acetic (S-KP), 3-oxo-1-piperazine acetic (U-KP), and 2-oxo-1,4-piperazine diacetic (3-KP) acids have been synthesized and the interconvertibility between these cyclic amides and their unsubstituted linear amino acid analogues, ethylene-diamine-N,N′-diacetic (S-EDDA), -N,N-diacetic (U-EDDA), and -N,N,N′-triacetic (ED3A) acids respectively, was demonstrated.The acid dissociation constants of the various amino acids were determined potentiometrically at 25° and μ = 0.1 M(KNO3) and the results were compared with the hydrogen ion affinities of related compounds. Dissociation schemes were proposed for all the compounds based on these results. Rationalizations of the linear amino acid and the cyclic amide dissociation constants were made in terms of the effects of cyclization and the inductive effects of neighboring groups. These rationalizations were found to be helpful in clarifying the dissociation schemes previously proposed for several of the linear amino acids.

Formation and occurrence of N-malonylphenylalanine and related compounds in plants

1968 ◽  
Vol 46 (8) ◽  
pp. 797-806 ◽  
Author(s):  
N. Rosa ◽  
A. C. Neish
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Plant Species ◽  
Isolation Procedure ◽  
Plant Kingdom ◽  
Feeding Experiments ◽  
Leucine Isomers ◽  
Related Compounds

Shoots of barley seedlings when fed D-phenylalanine convert the amino acid to N-malonylphenylalanine. Some N-acetylphenylalanine is obtained at the same time but this may be an artifact of the isolation procedure since it is readily formed by decarboxylation of the malonylphenylalanine. Feeding experiments with the D- and L-isomers of phenylalanine, valine, leucine, isoleucine, tyrosine, tryptophan, alanine, and glutamic acid showed that barley shoots form the malonyl derivative from all the D-isomers whereas little, if any, is formed from the L-isomers. Similar experiments with phenylalanine and leucine isomers, using seven different plant species, showed that the ability to conjugate the D-isomers (but not the L-isomers) was found in all of the plants tested. It was also observed that the ether-soluble acidic conjugates of a variety of amino acids, possibly malonyl derivatives, occur widely throughout the plant kingdom.

scholarly journals Transcriptomic Analysis of Short-Term Salt Stress Response in Watermelon Seedlings

2020 ◽  
Vol 21 (17) ◽  
pp. 6036
Author(s):  
Qiushuo Song ◽  
Madhumita Joshi ◽  
Vijay Joshi
Keyword(s):  
Amino Acids ◽  
Salt Stress ◽  
Amino Acid ◽  
Photosystem Ii ◽  
Free Amino Acids ◽  
Free Amino ◽  
Molecular Mechanisms ◽  
Differentially Expressed ◽  
Short Term ◽  
Salt Stress Response

Watermelon (Citrullus lanatus L.) is a widely popular vegetable fruit crop for human consumption. Soil salinity is among the most critical problems for agricultural production, food security, and sustainability. The transcriptomic and the primary molecular mechanisms that underlie the salt-induced responses in watermelon plants remain uncertain. In this study, the photosynthetic efficiency of photosystem II, free amino acids, and transcriptome profiles of watermelon seedlings exposed to short-term salt stress (300 mM NaCl) were analyzed to identify the genes and pathways associated with response to salt stress. We observed that the maximal photochemical efficiency of photosystem II decreased in salt-stressed plants. Most free amino acids in the leaves of salt-stressed plants increased many folds, while the percent distribution of glutamate and glutamine relative to the amino acid pool decreased. Transcriptome analysis revealed 7622 differentially expressed genes (DEGs) under salt stress, of which 4055 were up-regulated. The GO analysis showed that the molecular function term “transcription factor (TF) activity” was enriched. The assembled transcriptome demonstrated up-regulation of 240 and down-regulation of 194 differentially expressed TFs, of which the members of ERF, WRKY, NAC bHLH, and MYB-related families were over-represented. The functional significance of DEGs associated with endocytosis, amino acid metabolism, nitrogen metabolism, photosynthesis, and hormonal pathways in response to salt stress are discussed. The findings from this study provide novel insights into the salt tolerance mechanism in watermelon.

Dissociation between plasma and brain amino acid profiles and short-term food intake in the rat

1994 ◽  
Vol 266 (5) ◽  
pp. R1675-R1686 ◽  
Author(s):  
G. H. Anderson ◽  
E. T. Li ◽  
S. P. Anthony ◽  
L. T. Ng ◽  
R. Bialik
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Short Term ◽  
Egg Albumin ◽  
Amino Acid Profiles ◽  
Total Mixture ◽  
Brain Amino Acid

The relationship between plasma and brain amino acids and short-term food intake after administration of albumin, or its constituent amino acids, was examined. Rats given protein (0.85 g chicken egg albumin) or an amino acid mixture patterned after egg albumin reduced their food intake during 1 h of feeding beginning 30 min after gavage. Similarly, when given separately, the essential (EAA) and nonessential amino acid (NEAA) fractions of egg albumin caused comparable decreases in food intake. As the dose increased from 0.5 to 1.5 g the duration of anorexia prolonged to 12 h. Little change occurred in plasma amino acids at 30 and 60 min after albumin at 0.85 g, although many increased by 25-50% at 60 min after 1.5 g. Marked changes in plasma occurred after gavage with the total mixture of constituent free amino acids and after either EAA or NEAA fractions. Brain amino acid concentrations were little affected by albumin and did not show consistent changes after the amino acid treatments. Thus the reductions in food intake after ingestion of albumin or of its constituent amino acids were not predicted from the resulting changes in either plasma or brain concentrations of amino acids.

scholarly journals Short‐term Regulation of Amino Acid Transporters by Amino Acids

2015 ◽  
Vol 29 (S1) ◽  
Author(s):  
Julia Jando ◽  
Josua Jordi ◽  
François Verrey
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Transporters ◽  
Short Term

scholarly journals Branched-chain amino acid catabolism depends on GRXS15 through mitochondrial lipoyl cofactor homeostasis

2020 ◽  
Author(s):  
Anna Moseler ◽  
Inga Kruse ◽  
Andrew E. Maclean ◽  
Luca Pedroletti ◽  
Stephan Wagner ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Degradation Products ◽  
Tca Cycle ◽  
Cluster Assembly ◽  
Amino Acid Catabolism ◽  
Metabolic Defects ◽  
Branched Chain Amino Acid ◽  
Branched Chain ◽  
Dependent Processes

AbstractIron-sulfur (Fe-S) clusters are ubiquitous cofactors in all life and are used in a wide array of diverse biological processes, including electron transfer chains and several metabolic pathways. Biosynthesis machineries for Fe-S clusters exist in plastids, the cytosol and mitochondria. A single monothiol glutaredoxin (GRX) has been shown to be involved in Fe-S cluster assembly in mitochondria of yeast and mammals. In plants, the role of the mitochondrial homologue GRXS15 has only partially been characterized. Arabidopsis grxs15 null mutants are not viable, but mutants complemented with the variant GRXS15 K83A develop with a dwarf phenotype. In an in-depth metabolic analysis, we show that most Fe-S cluster-dependent processes are not affected, including biotin biosynthesis, molybdenum cofactor biosynthesis and the electron transport chain. Instead, we observed an increase in most TCA cycle intermediates and amino acids, especially pyruvate, 2-oxoglutarate, glycine and branched-chain amino acids (BCAAs). The most pronounced accumulation occurred in branched-chain α-keto acids (BCKAs), the first degradation products resulting from deamination of BCAAs. In wild-type plants, pyruvate, 2-oxoglutarate, glycine and BCKAs are all metabolized through decarboxylation by four mitochondrial lipoyl cofactor-dependent dehydrogenase complexes. Because these enzyme complexes are very abundant and the biosynthesis of the lipoyl cofactor depends on continuous Fe-S cluster supply to lipoyl synthase, this could explain why lipoyl cofactor-dependent processes are most sensitive to restricted Fe-S supply in GRXS15 K83A mutants.One-sentence summaryDeficiency in GRXS15 restricts protein lipoylation and causes metabolic defects in lipoyl cofactor-dependent dehydrogenase complexes, with branched-chain amino acid catabolism as dominant bottleneck.

scholarly journals 386 Past, present and future of protein and N metabolism in ruminants

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 169-170
Author(s):  
Gerald B Huntington ◽  
Joan H Eisemann
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Public Perception ◽  
National Research Council ◽  
Protein Composition ◽  
Publishing Research ◽  
Quantitative Information ◽  
Future Research ◽  
Ruminant Species ◽  
N Metabolism

Abstract By 1900, research identified urea, ammonia, and protein as the basic components of N metabolism in ruminants. Energy and protein metabolic interactions were outlined, amino acids were individually recognized as constituents of protein molecules, and the concept of enzyme-catalyzed reactions was established. Research stations were publishing research results and feeding recommendations. By 2000, the National Research Council built on the work of Henry and Morrison to create and revise publications of nutrient requirements for various classes of ruminants. Use of surgically altered animals, isotopically labelled molecules, and standardized laboratory analyses created quantitative information on ingestion, digestion, absorption, and metabolism of N-containing compounds. Protein composition and structure as well as the role of protein turnover to determine the concentration of cellular proteins were elucidated. Hypothesis-driven, statistically valid experimental designs created quantitative information on protein and amino acid requirements. Methionine was identified as the likely first-limiting amino acid for several ruminant species and production states. The internet and the advent of international symposia provided links among researchers around the globe. Today, multidisciplinary research teams are needed to enlarge the data base, to describe proteomics and metabolomics, and to integrate “big data” into insightful and useful models. Those models currently use or estimate rates and daily amounts of ruminal (in)degradability of dietary protein, ammonia production, urea recycling, microbial protein synthesis, postruminal protein digestion, metabolic fecal nitrogen, and amino acid absorption and metabolism. They predict use of metabolizable amino acids for maintenance, milk yield, growth, and fetal growth. Directions of future research include integration of functional roles of amino acids into recommended dietary supply and requirements, and focus on solutions to challenges presented by climate change, (in)sustainability of livestock production, and changes in public perception of humans’ use of ruminants and other animals.

scholarly journals Amino acid and ureide transport in the xylem of symbiotic soybean plants during short-term flooding of the root system in the presence of different sources of nitrogen

2006 ◽  
Vol 18 (2) ◽  
pp. 333-339 ◽  
Author(s):  
André Luís Thomas ◽  
Ladaslav Sodek
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
N2 Fixation ◽  
Xylem Sap ◽  
Organic N ◽  
N Source ◽  
Root Hypoxia ◽  
N Metabolism ◽  
Soybean Plants ◽  
Different Sources

The transport of organic N compounds to the shoot in the xylem sap of nodulated soybean plants was investigated in an attempt to better understand the changes in N metabolism under root hypoxia (first 5 days of flooding), with different sources of N in the medium. NO3- is beneficial for tolerance of plants to waterlogging, whereas other N sources such as NH4+ and NH4NO3, are not. Nevertheless, in the presence of NH4+ high levels of amino acids were transported in the xylem, consistent with its assimilation. Some increase in the transport of amino acids was also seen with NO3- nutrition during waterlogging, but not with N-free medium. Ureide transport in the xylem was severely reduced during waterlogging, consistent with impaired N2 fixation under these conditions. The relative proportions of some amino acids in the xylem showed dramatic changes during treatment. Alanine increased tremendously under root hypoxia, especially with NH4+ as N source, where it reached near 70 % of the total amino acids present. Aspartic acid, on the other hand, dropped to very low levels and was inversely related to alanine levels, consistent with this amino acid being the immediate source of N for alanine synthesis. Glutamine levels also fell to a larger or lesser extent, depending on the N source present. The changes in asparagine, one of the prominent amino acids of the xylem sap, were most outstanding in the treatment with NO3-, where they showed a large increase, characteristic of plants switching from dependence on N2 fixation to NO3- assimilation. The data indicate that the lesser effectiveness of NH4+ during waterlogging, in contrast to NO3-, involves restricted amino acids metabolism, and may result from energy metabolism being directed towards NH4+ detoxification.

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