Category: Home

Amino acid synthesis pathway in plants

Amino acid synthesis pathway in plants

Google Pathwaj Susuki, A. Agarose gel Nutrient timing for pre-workout nutrition and NanoDrop spectrophotometer Thermo were used to Improve energy and motivation synthexis quality sjnthesis samples. Essential amino acids are in Capitals. This UAG codon is followed by a PYLIS downstream sequence. When present, SeC is usually confined to active sites of proteins involved in reduction-oxidation redox reactions.

Amino acid synthesis pathway in plants -

Here, we investigated the dynamic changes of free amino acid contents in response to N deficiency and forms in tea plant roots, and systemically identified the genes associated amino acid contents in individual metabolism pathways.

Our results showed that glutamate-derived amino acids are the most dynamic in response to various forms of N and N deficiency. We then performed transcriptomic analyses of roots treated with N deficiency and various forms of N, and differentially expressed amino acid metabolic genes in each pathway were identified.

The analyses on expression patterns and transcriptional responses of metabolic genes to N treatments provided novel insights for the molecular basis of high accumulation of theanine in tea plant root. These analyses also identified potential regulatory genes in dynamic amino acid metabolism in tea plant root.

Furthermore, our findings indicated that the dynamic expression levels of CsGDH, CsAlaDC, CsAspAT, CsSDH, CsPAL, CsSHMT were highly correlated with changes of amino acid contents in their corresponding pathways.

Herein, this study provides comprehensive insights into transcriptional regulation of amino acid metabolism in response to nitrogen deficiency and nitrogen forms in tea plant root. Tea is one of the most popular nonalcoholic beverages in the world. It is consumed daily by billions of people worldwide for its attractive taste and significant health benefits, which are conferred by the high abundance of polyphenols, caffeine, and amino acids 1 , 2 , 3.

Among these amino acids, theanine Thea , glutamine Gln , glutamic acid Glu and arginine Arg are the most abundant 4 , 5. Characteristically, Thea is a unique non-protein amino acid in tea plant Camellia sinensis L.

The health benefits of Thea include induction of relaxation, anti-paralysis induced by caffeine, anti-tumor, anti-obesity and body weight control.

These benefits have been extensively studied and reported by more than research articles and nearly review papers 9. Free amino acids also contribute to the formation of tea aroma compounds and a large number of other secondary metabolites essential for tea plant growth and stress adaption 10 , However, the molecular mechanism of amino acid metabolism regulation in tea plant is still poorly understood.

In plants, amino acids are synthesized through branched pathways 12 , 13 Fig. Oxaloacetate is the initial metabolite for synthesis of asparagine Asp , aspartate Asn , threonine Thr , lysine Lys , methionine Met , and isoleucine Ile.

Alanine Ala , leucine Leu and valine Val are synthesized from pyruvate. Aromatic amino acids tryptophan Trp , tyrosine Tyr and phenylalanine Phe are the products of the shikimate pathway. In tea plant, Thea is synthesized from Glu and ethylamine EA by theanine synthetase TS EA is likely produced from alanine under the catalysis of alanine decarboxylase Schematic diagram of amino acid metabolism pathways in tea plants.

P3, amino acids were derived from Asp pathway consisting of Asp, Thr, Ile, Met, Lys, Asn. P4, amino acids were derived from pyruvate pathway consisting of Val and Leu. P5, amino acids were derived from aromatic amino acid pathway consisting of Trp, Phe and Tyr. P6, amino acids were derived from 3-phosphoglycerate pathway consisting of Cys, Ser and Gly.

Glu, glutamate; Gln, glutamine; Arg, arginine; Pro, proline; Thea, theanine; Asp, aspartate; Thr, threonine; Lys, lysine; Ile, isoleucine; Aspn, asparagine; Val, Valine; Leu, Leucine; Trp, tryptophan; Phe, Phenylalanine; Tyr, Tyrosine; Cys, cysteine; Gly, Glycine; Ser, serine.

Amino acid catabolism have been clearly described in animals, however, limited information of amino acid catabolism is available in plants. Hildebrandt et al. summarized the catabolic pathways of amino acids in land plants. Generally, amino acids are catabolized by oxidative deamination, oxidative decarboxylation, and transamination.

These reactions are catalyzed by amino acid dehydrolases, decarboxylases and aminotransferases, respectively. Gln, Asn and Arg are also hydrolyzed by asparaginase, glutaminase, and arginase to release amide groups The accumulation of free amino acids is resultant of biosynthesis and catabolism.

Previous studies showed that feedback inhibition loops control amino acid biosynthesis in plants Here, the accumulation of an amino acid inhibits the transcription or the activities of the enzymes in its biosynthesis pathway 18 , 19 , Expression of feedback-insensitive form of enzymes resulted in higher levels of the corresponding amino acids 17 , The central role of amino acid catabolism is to adjust the amino acid pool size, especially under stress conditions Some regulatory enzymes in amino acid metabolism have been identified in model plants.

However, studies have demonstrated that amino acid metabolism is regulated by a large number of general and specific factors, and the regulation differs significantly between species, tissues, developmental stages, various stresses and stages of stress responses 12 , 22 , Members of genes encoding isoforms of enzymes catalyzing a specific step in amino acid metabolism also usually play different roles in these processes 24 , In tea plants Camellia sinensis L.

Basically, application of N fertilizers increases amino acid biosynthesis in tea plant. In addition, intensive studies showed that shading treatment significantly increases free amino acid accumulation in tea plant 29 , 35 , The alteration of amino acid metabolism under various conditions was suggested to be associated with gene expression and activity of glutamine synthetase GS , glutamate synthase GOGAT , glutamate dehydrogenase GDH and other amino acid biosynthesis genes 26 , 34 , However, only a few genes involved in amino acid metabolism and genes associated with changes in amino acid accumulation have been identified in tea plants.

As the most abundant free amino acid in tea plant, Thea was first discovered by Sakato Thea metabolism has been studied for more than 60 years, but its molecular mechanism remains largely unknown. It has been reported that TS catalyzes the biosynthesis of Thea from Glu and EA 14 Fig. The gene encoding TS was recently identified in tea plant However, Cheng et al.

They further speculated that high accumulation of EA is why tea plant can synthesize large amount Thea. EA was suggested to be synthesized from alanine under the catalysis of alanine decarboxylase.

In the other hand, Thea could be degraded into EA and Glu by theanine hydrolase Until now, the gene encoding for theanine hydrolase has not been identified yet. Finally, it is noteworthy that Thea is mainly synthesized in roots and is transported through the vascular system to tea plant shoots 41 , 42 , 43 , 44 , The complete sequencing of the tea plant genome now provides a means to systematically identify genes encoding enzymes in individual amino acid metabolic steps 38 , The responses to N forms of free amino acid production in each synthesis pathway were analyzed.

The corresponding genes in amino acid metabolic pathways were identified, and the expression patterns of these genes were characterized in roots by RNA-seq analyses. These analyses have identified fundamental and regulatory mechanisms of amino acid metabolism in tea plant.

To study the regulation of amino acid metabolism in tea plant roots, we hydroponically cultured tea plants to produce well developed roots Fig. After 10 days, tea plants under these treatments developed varied root architecture system Fig.

Given that root architecture is responsive to N status for better nutrient foraging 47 , 48 and is associated with amino acid levels 49 , this result suggested there were differences in the endogenous amino acid contents in these tea plant roots.

Schematic of experiment procedure and composition of amino acids in the tea plant roots under the treated conditions. A Two-year-old cuttings of tea plant were recorded after hydroponics cultivation for 45d in a basal nutrient solution.

The contents of main amino acids derived from Glu pathway Glu, Gln, Arg, Pro, and Thea , Asp pathway Asp, Ile, Thr, Lys , pyruvate pathway Ala and Leu , aromatic amino acid pathway Phe and Tyr and 3-phosphoglycerate pathway Ser and Gly were measured under the treated conditions.

Among these amino acids examined, theanine content was the highest and reached over 1. Contents of Ile, Asp, Ser, and Pro were similar, and the contents of Ala, Leu, Thr, Lys, Gly and Phe were low in tea plant roots under the treated conditions. Effects of N forms and 0N on accumulation of amino acids in tea plant roots.

Ala: Alanine; Ser: Serine; Gln: Glutamine; Pro: Proline; His: Histidine; Gly: Glycine; Arg: Arginine; Thr: Threonine; Lys: Lysine; Tyr: Tyrosine; Thea: Theanine; Leu: Leucine; Phe: Phenylalanine; Asp: Aspartic acid; Ile: Isoleucine; Glu: Glutamic acid.

Conversely, the contents of Glu-derived amino acids including Gln, Arg, Pro and Thea changed significantly under the different conditions. These results indicate that Glu pathway is not only the main flux of amino acid metabolism, but it is also most responsive to N deficiency and N forms.

Thea is synthesized from Glu and EA. EA is the product of Ala decarboxylation. Contrastingly to the Glu contents, Ala contents significantly changed in accordance with Thea contents.

This correlation suggested that formation of EA from Ala may comprise the main regulatory step of Thea synthesis. Surprisingly, a direct supply of equimolar EA 1. This implied, when low level of EA as the sole nitrogen source, EA is not used in priority as precursor to synthesize Thea but rather used for the synthesis of all amino acids.

The contents of Asp-derived Thr and Lys both changed ~1. Meanwhile, the accumulation of 3-phosphoglycerate pathway-derived Ser and Gly also showed similar response patterns. In addition, branched-chain amino acids Leu and Ile and aromatic amino acids Phe and Tyr showed similar and slight changes Figs.

These results demonstrated that metabolism of amino acids in the same pathway is likely regulated as a module, and may be controlled by genes encoding key enzymes catalyzing the common steps. The total RNA was used to prepare cDNA libraries for transcriptomic analysis.

Four biological replicates were performed. Therefore, 20 cDNA libraries were sequenced using the Illumina HiSeq platform. In total, The clean reads were mapped to the reference genome A total of genes were identified and their expression levels in the roots under the different treatments were measured Table S3.

The comparisons found , , and DGEs for these comparisons, respectively Fig. A Venn diagram was constructed to investigate the numbers of co-expressed and uniquely expressed DEGs in response to different N forms Fig. A total of co-expressed DEGs were obtained under treatment of all four N forms.

An overview on differentially expressed genes responsive to different forms of N in tea plant root. DEGs, differentially expressed genes. adj FPKM, adjusted Fragment Per Kilo base of exon model per Million mapped reads.

Red indicates a gene up-regulated at that treatment, while green indicates down-regulated expression. D The OPLS-DA analysis of amino acids in tea plant roots under treatments with different forms of N.

OPLS-DA analysis was performed by SIMCA F Hierarchical clustering representing relative expression levels of DEGs related to amino acids metabolism. To examine the effect of different N forms on amino acid accumulation, an OPLS-DA analysis was performed to analyze 15 amino acids in tea roots under those treatments.

Amino acid profiling showed that treatments of different N forms and N deficiency affected amino acids accumulation in tea roots Fig.

Subsequently, the DEGs encoding enzymes in amino acid biosynthesis and the first step of amino acid degradation were also identified.

A total of genes encoding 75 enzymes were identified and their expression levels were presented in Table S6. As shown in Fig. The two precursors of Thea synthesis are EA and Glu which are produced by CsAlaDC, CsGDHs and CsGOGATs, respectively Fig.

EA and Glu are catalyzed by CsCsTSI or CsGSs to synthesize Thea. Under this treatment, within the amino acid biosynthetic genes, CsAlaDC , CsCsTSI , CsGS TEA Impressively, total FPKM of these 3 genes accounted for Furthermore, total FPKM of CsAlaDC , CsGDHs , CsGOGATs , CsCsTSI and CsGSs accounted for as high as Therefore, the high expression of these Thea-related genes provide strong basis for the highly abundant accumulation of Thea in tea plant roots.

Identification of DEGs encoding enzymes related to Glu pathway. A The DEGs encoding enzymes related to synthesis and first step degradation of the Glu pathway. C Quantitative real-time PCR validation for potential candidate genes.

The relative expression levels and FPKM values are shown. CsAlaDC was not only the 1 st most highly expressed amino acid synthetic gene Table S6 , it was also the 5 th most highly expression genes within all genes in tea plant roots under EA-N condition Table S3.

Although CsTSI and CsGS TEA These results suggested CsAlaDC plays more regulatory role in Thea biosynthesis. Glu is the initial product of ammonia assimilation and provides α-amino group for all other amino acid biosynthesis.

It also provides carbon skeleton for Pro abd Arg biosynthesis. Therefore, Glu plays a central role in amino acid metabolism in plants Arg can be hydrolyzed by arginase into urea and ornithine Orn and was finally degraded into ammonium and carbon dioxide. Alternatively, Arg can also be decarboxlated by Arginine decarboxylase CsADC and was further metabolized into polyamines.

These results suggested CsADC regulates Arg catabolism into polyamines under N sufficient condition, and CsARG mediates Arg catabolism to ammonium under N deficient condition. To validate the expression profiles of DEGs obtained from RNA-seq dataset, five DEGs related to the Glu pathway were selected for qRT-PCR, including CsGDH TEA The results of qRT-PCR in each treatment closely corresponded to the transcript levels of the RNA-seq dataset Fig.

Asp is synthesized from 2-oxaloacetate and Glu under the catalysis of aspartate aminotransferase AspAT Fig. Asp can then act as precursor to produce Thr, Met, Lys and Ile which are essential for mammals In this pathway, some genes encoding 25 amino acid metabolic enzymes were identified from transcriptome datasets Fig.

Identification of DEGs encoding enzymes related to Asp and pyruvate pathway. A The DEGs encoding enzymes related to synthesis and first step degradation pathway of Asp and pyruvate-derived amino acids. In this study, we observed that Asp contents in tea plant roots were generally stable under the treatments Fig.

In addition, CsAK catalyses the first step in the conversion of Asp to Lys, Thr, Ile and Met Fig. Threonine synthase THS catalyzes Thr synthesis Fig. CsTHS TEA These results suggested CsTHS expression is probably feedback regulated by Thr accumulation in tea plant roots.

Although Ile and Leu are derived from Asp and pyruvate, respectively, they are both branched-chain amino acids and share common metabolic enzymes including acetolactate synthase AHAS , ketol-acid reductoisomerase KARI , dihydroxy-acid dehydratase DHAD and branched-chain amino acid aminotransferase BCAT Fig.

Consistently, within 40 genes encoding 8 enzymes in Ile and Leu metabolism, only CsAHAS TEA Ala is synthesized from pyruvate by Alanine aminotransferase AlaT Fig. CsAlaT TEA These results suggested an importantly role of CsAlaT in Ala biosynthesis. Four representative genes CsAspAT , CsTHS , CsAK , CsAlaT were selected for qRT-PCR analysis.

Transcript levels determined by qRT-PCR were perfectly matched with those of the RNA-seq dataset Fig. The aromatic amino acids AAA Phe, Tyr, and Trp are not only essential components of protein synthesis, but also provide the precursors for the synthesis of a wide range of secondary metabolites in plants The aromatic amino acids are synthesized via the shikimate pathway, which initiates from phosphoenolpyruvate PEP and erythrose 4-phosphate E-4P.

The regulation of AAA biosynthesis via the shikimate pathways has been largely unknown in tea plant. In total, 92 annotated genes encoding 19 major enzymes in the shikimate pathway were identified Fig. The initial step of shikimate pathway is the formation of 3-dehydroquaianate from PEP and E-4P and this reaction is catalyzed by 3-deoxy-d-arabino-heptulosonate phosphate synthase DAHPS.

Within 5 genes encoding CsDAHPS, one gene TEA However, EA-N did not induce the expression of genes encoding biosynthetic enzymes in shikimate pathways Fig. Characteristically, EA-N significantly repressed the expression of 6 genes encoding Phenylalanine ammonia-lyase PAL.

Phe is a precursor for a large number of important secondary metabolites, including phenylpropanoids, flavonoids, lignin, anthocyanins, catechins, and many other metabolites The first step of Phe catabolism towards these metabolites is catalyzed by PAL. These results suggested N, especially EA-N, represses Phe catabolism through regulating the expression of CsPALs.

Shikimate is a critical precursor for aromatic amino acid synthesis. Arogenate also serves as a common substrate for both Phe and Tyr synthesis. TAT catalyzes the first step of Tyr degradation. To further validate our results, three important genes CsPAL , CsTAT and CsTPS were chosen for qRT-PCR analysis.

The expression levels of these genes using qRT-PCR were in good accordance with corresponding transcript levels of the RNA-seq dataset Fig. It was documented that Gly, Cys, and Ser are derived from 3-phosphoglycerate in plants, and are synthesized through 6 reactions catalyzed by 6 enzymes.

Genes encoding biosynthetic and catabolic enzymes involved in 3-Phosphoglycerate pathway were screened. In total, 77 annotated genes encoding 10 major enzymes in 3-phosphoglycerate pathways were identified Fig. Notably, only three DEGs encoding dphosphoglycerate dehydrogenase CsPGDH , Serine hydroxymethyltransferase CsSHMT and Serine O-acetyltransferase CsSOA were observed under various forms of N treatments.

Importantly, both CsSHMT and CsSOA have two members in tea plant, and these showed differential responses to N treatments. The gene expression of CsSHMT TEA Likewise, the gene expression of CsSOA TEA While, a significant decrease of transcript levels of CsSOA TEA Identification of DEGs encoding enzymes related to 3-phosphoglycerate pathway.

A The DEGs encoding enzymes related to synthesis and first step degradation pathway of amino acids from 3-phosphoglycerate pathway.

To further validate our results, three important genes CsPGDH , CsSHMT and CsSOA were chosen for qRT-PCR analysis.

The expression levels of these genes using qRT-PCR were consistent with corresponding transcript levels of the RNA-seq dataset Fig. In general, the contents of secondary metabolites significantly affect the quality of tea products Among the various metabolic products, amino acids greatly contribute to the quality of green tea.

Previous studies showed that N forms and N level significantly affect amino acid metabolism, thereby modulating amino acid levels in tea roots and shoots. It is important to achieve a comprehensive understanding of the underlying molecular basis of how amino acid biosynthesis and catabolism are regulated at molecular level by N forms in tea plant root.

Several studies have explored amino acid contents and corresponding molecular changes that occur in tea plants in response to nutritional and environmental conditions 26 , 27 , 30 , 43 , 54 , 55 , 56 , Glu-derived pathway amino acids are most abundant and most dynamic in roots of tea plants.

Metabolism of amino acids derived from same precursors may be regulated in modules Figs. Notably, a direct supply of EA in the culture medium did not increase Thea synthesis, suggesting that Thea might be as a form of nitrogen storage only when N nutrition is sufficient.

In present study, we used same amount N concentration as normal nutritional solution. In this condition, the tea plants prefer to utilize EA-N to meet their need for N Fig.

S2 , but not directly providing the substrate for Thea synthesis. Bioavailability of N correlates closely to both tea yield and quality of processed tea 26 , 27 , Nutrient supplementation level is a critical factor greatly influencing both yield and quality of tea 7 , In addition, Ruan et al.

In summary, these findings are consistent with those of this study of amino acids contents in tea roots under various N forms treatments Fig.

Increasing evidences showed that N forms and levels relate closely to changes of amino acids content of tea roots and leaves 26 , 27 , 30 , However, a comprehensive investigation into the molecular basis underlying amino acids metabolism in tea roots is still absent.

For example, Huang et al. Actually, previous studies reported that many amino acids are mainly synthesized in tea root, and are then transported from root to shoot 41 , 44 , Yang et al. Thus, the tissue-specific response of gene expression could not be elucidated Recently, Liu et al. Deep RNA-sequence technology is a powerful tool to systemically identify key gene candidates in many plants, such as Poplar 60 , Arabidopsis 61 , Camellia sinensis 30 , 62 , This suggested that the genes involved in N absorption, assimilation and metabolism were remarkably affected by the forms of N.

Combined with the RNA-seq data, we identified the genes encoding enzymes involved in five main amino acid metabolism pathways. Notably, FPKM of CsAlaDC , CsGDHs , CsGOGATs , CsCsTSI and CsGSs of Thea-related amino acid biosynthetic genes accounted for as high as We speculate that high expression of these genes conferred the highly specific synthesis and accumulation of Thea in tea plant root.

In Asp and pyruvate pathway, aspartate aminotransferase AspAT catalyzed 2-oxaloacetate and Glu to synthesize Asp. Asp can be hydrolyzed by asparate kinase CsAK. In addition, Phe is a precursor for many tea secondary metabolites. The first step of Phe catabolism is catalyzed by PAL. Our results showed EA-N significantly represses Phe catabolism by down-regulated of CsPALs , suggesting that less metabolism of Phe occurred in this treatment of shikimate pathway.

Moreover, due to the significant variation of Ser and Gly contents under different forms of N and levels, we also found a key regulatory DEG CsSHMT in the 3-Phosphoglycerate pathway, which was significantly responsive to N forms treatment. We have identified some key regulatory genes in the five main pathways of amino acid metabolism, which provided a vital and useful clue to comprehensively understand the changes of amino acid accumulation in tea roots.

However, the molecular mechanism related to how these potential genes control amino acid metabolic flux in tea roots remains unclear. Future studies of these regulatory genes will be needed to further determine the mechanistic effects. In this study, integrated transcriptome and metabolites amino acids analyses provide new insights into amino acid metabolism of tea roots.

The results showed that Glu-derived pathway amino acids are the most abundant and most dynamic in tea roots. Metabolism of amino acids derived from same precursors may be regulated as modules. Moreover, the amino acid composition in tea roots is significantly regulated in response to different forms of N and N deficiency.

This study first systematically identified the key potential genes encoding biosynthetic enzymes as well as enzymes catalyzing the initial catabolic steps of amino acids, which can be used for providing a reference and guidance for further research on the role of these potential genes in amino acid metabolism of tea plant roots.

Two-year-old tea cutting seedings Camellia sinensis L. shuchazao were collected from Dechang Tea Fabrication Base at Shucheng County in Anhui province, China, and used for the hydroponic culture experiments in this study. In the hydroponic experiment, roots of the seedlings collected were washed in tap water to remove the soil on the root surface, and then tea cutting seedlings of similar size with 10—12 leaves were selected and transplanted into plastic pots containing 10 liters of tap water.

After 3 days, seedlings were transferred to 5-litre plastic bucket 5 plants per bucket for hydroponic culture. Afterwards, the complete basal nutrient solution was supplied for one month. The composition of the nutrient solution was used as described 50 : 0. The pH of the nutrient solution was adjusted to 4.

HCl 1. The determination of free amino acids in tea plant roots was performed as described 64 , 65 with minor modifications. Briefly, a HPLC system Waters coupled to a fluorescence detector Waters and an ultraviolet-visible detector Waters was used in this study.

Thea standard was purchased from Sigma Chemical Company St. Louis, MO, USA , and other amino acid standards were purchased from Waters Corporation Milford, Massachusetts, U. Total contents of free amino acids content were calculated as the sum of each individual free amino acid.

Total RNA was extracted from root samples using the RNA pure plant Kit Tiangen, Beijing, China combined with the improved CTAB method described previously Agarose gel electrophoresis and NanoDrop spectrophotometer Thermo were used to determine the quality of samples. Libraries were then constructed and sequenced using the Illumina Genome Analyzer Solexa.

All samples for Digital Gene Expression were run in four biological replicates, and each replicate was a mixture of roots from 5 individual tea seedlings. Unique mapped reads were used for further analysis. The fragments per kilobase of transcript sequence per millions of base pairs sequenced FPKM presented the normalized gene expression NR annotation and Gene ontology GO analysis were used to predict gene function, and identify the functional category distribution frequency GO classifications were obtained according to molecular function, biological process, and cellular component.

KEGG annotation http:www. To validate the genes expression patterns displayed by RNA-seq results, a total of 16 DEGs were randomly selected and analyzed using quantitative real-time reverse transcription PCR qRT-PCR. qRT-PCR amplification was performed using primers designed by Primer 6.

Three biological replicates were included. The expression levels of targeted genes were normalized based on the expression levels of CsACTIN in different root samples All the primers for genes amplification using qRT-PCR were listed in the Supplemental Table S The datasets analyzed during the current study are available from the corresponding author on reasonable request.

Cabrera, C. Beneficial effects of green tea-A review. Article CAS PubMed Google Scholar. Rogers, P. Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together. Psychopharmacology , — Vuong, Q.

L-Theanine: properties, synthesis and isolation from tea. Food Agric. Harbowy, M. Tea chemistry. Plant Sci. Article CAS Google Scholar. Feng, L. et al. Determination of quality constituents in the young leaves of albino tea cultivars. Food Chem. Differentiation of green, white, black, oolong, and pu-erh teas according to their free amino acids content.

Article PubMed CAS Google Scholar. Deng, W. Biosynthesis of theanine γ-ethylamino-l-glutamic acid in seedlings of Camellia sinensis.

Wan, X. Tea Secondary Metabolites eds. Sharma, E. L-Theanine: An astounding sui generis integrant in tea. Wang, W. Transcriptomic analysis reveals the molecular mechanisms of drought-stress-induced decreases in Camellia sinensis leaf quality.

PubMed PubMed Central Google Scholar. Zhang, X. Crop J. Less, H. Principal transcriptional programs regulating plant amino acid metabolism in response to abiotic stresses. Plant Physiol. Article CAS PubMed PubMed Central Google Scholar. Pratelli, R. Regulation of amino acid metabolic enzymes and transporters in plants.

Sasaoka, K. Some Properties of the Theanine Synthesizing Enzyme in Tea Seedlings. Taketo, T. L-alanine as a precursor of ethylamine in Camellia sinensis. Phytochemistry 13 , — Article Google Scholar.

Hildebrandt, T. Amino acid catabolism in plants. Plant 8 , — Fowden, L. Aspects of Amino Acid Metabolism in Plants. Falcone : Mechanisms of participation of ATP in enzymic syntheses. Broquist , H. Snell : Studies of the mechanism of histidine synthesis in lactic acid bacteria.

Brummond , D. Burris : Reactions of the tricarboxylic acid cycle in green leaves. Cantoni , G. Cohen , G. Hirsch , S. Wiesendanger et B. Paris , — PubMed CAS Google Scholar. Cohen , P. In: Chemical Pathways of Metabolism, vol. Greenberg , editor. New York: Academic Press, Inc.

Conn , E. Young : Oxidative phosphorylation in lupine mitochondria. Coon , M. Robinson and B. Bachhawat : Enzymatic studies on the biological degradation of the branched chain amino acids.

Damodaran , M. Nair : Glutamic acid dehydrogenase from germinating seeds. Davis , B. Davison , D. Elliott : Enzymic reaction between arginine and fumarate in plant and animal tissues. Nature Lond. Denes , G. Experientia Basel 9 , 24—25 et Biophysica Acta 15 , — Gazda : Untersuchungen über die enzymatische Synthese der Säureamid- und Peptidbindung.

Die enzymatische Synthese von Glutamin in Lupinus albus. Acta physiol. Dewey , D. Hoare and E. Work : Diaminopimelic acid decarboxylase in cells and extracts of Escherichia coli and Aerobacter aerogenes.

Eberts jr. Burris and A. Riker : The metabolism of nitrogenous compounds by sunflower crown gall tissue cultures. Ehrensvärd , G. Reio , E. Saluste and R. Stjernholm : Acetic acid metabolism in Torulopsis utilis. Metabolic connection between acetic acid and various amino acids. Ellfolk , N.

On the specificity of aspartase. Studies on aspartase. On the effect of p H on aspartase. Elliott , W. Isolation of glutamine synthetase and glutamo-transferase from green peas.

Evstigneeva , Z. Kretovich : Difference in structure and chemical properties of asparagine and glutamine. Nauk SSSR. Cited from Chem. Fincham , J. The occurrence of glutamic dehydrogenase in Neurospora and its apparent absence in certain mutant strains. Transaminases in Neurospora crassa.

Fowden , L. of Bot. The enzymic decarboxylation of γ-methyleneglutamic acid by plant extracts. of Exper. Done : The enzymatic decarboxylation of γ-methyleneglutamic acid. Gibbs , M. Oxidation of hexose phosphate and pentose phosphate by cell-free extracts of pea leaves.

Horecker : The mechanism of pentose phosphate conversion to hexose monophosphate. With pea leaf and pea root preparations. Gilvarg , C. Greenberg , D. Metabolism of sulfur-containing compounds. Grisolia , S. Marshall : Recent advances in citrulline biosynthesis.

Grobbelaar , N. Steward : Pipecolic acid in Phaseolus vulgaris : Evidence on its derivation from lysine.

Hasse , K. Schumacher : Das Reaktionsprodukt der Decarboxylierung von 1-Glutaminsäure mittels pflanzlicher Decarboxylase. Hattori , S. Yoshtda and M. Hasegawa : Occurrence of shikimic acid in the leaves of gymnosperms. Plantarum Copenh. Hirsch , M. Horecker , B.

Smyrniotis : Purification and properties of yeast transaldolase. Smyrniotis , H. Hiatt and P. Marks : Tetrose phosphate and the formation of sedoheptulose diphosphate.

Smyrniotis and H. Klenow : The formation of sedoheptulose phosphate from pentose phosphate. Horowitz , N. The isolation of cystathionine. Johnston , J. Racusen and J. Bonner : The metabolism of isoprenoid precursors in a plant system.

Jones , M. Spector and F. Lipmann : Carbamyl phosphate, the carbamyl donor in enzymatic citrulline synthesis. Kalan , E. Srintvasan : Synthesis of 5-dehydroshikimic acid from carbohydrates in a cell-free extract.

Kasting , R. Delwiche : Ornithine, citrulline, arginine interconversions in higher plants. Meetings xxviii King , F. King and A. Warwick : The chemistry of extractives from hardwoods. Part III. Baikiain, an amino acid present in Baikiaea plurijuga. Kleipool , R. Wibaut : Mimosine Leucaenine.

Pays-Bas 69 , 37—44 Korzenovsky , M. Kowalsky , A. Wyttenbach , L. Langer and D. Koshland jr. Krebs , H. In: The Enzymes, vol. Sumner and K. Myrbäck , editors. Henseleit : Untersuchungen über die Harnstoffbildung im Tierkörper. Leach , S. Lindley : Structure of asparagine.

Levintow , L. Meister : [1] Enzymatic synthesis of d -glutamine and related hydroxamic acids. Reversibility of the enzymatic synthesis of glutamine; with appendix by M. γ-Glutamyl phosphate. Levy , L. Coon : [1] The role of formate in the biosynthesis of histidine. Biosynthesis of histidine from radioactive acetate and glucose.

Liverman , J. Ragland : Metabolism of sulfur in the Alaska pea. Meetings, vii—viii Lowy , P. Biophysics 47 , — Maas , W. Novelle and F. Lipmann : Acetylation of glutamic acid by extracts of Escherichia coli. Mac Vicar , R.

Burris : Studies on nitrogen metabolism in tomato with use of isotopically labeled ammonium sulfate. Mc Manus , I. Meiss , A. Connecticut Agricult. Meister , A. Metabolism of glutamine. Fraser : Enzymatic formation of L-asparagine by transamination. Miettinen , J. Virtanen : Nitrogen metabolism of the alder Alnus.

The absence of arginase and presence of glutamic acid decarboxylase. Miller , A. Waelsch : Enzymatic hydroxamic acid formation from aspartic acid. Mitsuhashi , S. Davis : [1] Aromatic biosynthesis. Conversion of 5-dehydroquinic acid to 5-dehydroshikimic acid by 5-dehydroquinase. et Biophysica Acta 15 , 54—61 Aromatic biosynthesis.

Conversion of quinic acid to 5-dehydroquinic acid by quinic dehydrogenase. et Biophysica Acta 15, — Morrison , J. Morrison , R. Myers , J. Adelberg : The biosynthesis of isoleucine and valine. Enzymatic transformation of the dihydroxy acid precursors to the keto acid precursors.

Nisman , B. Cohen , S. Wiesendanger and M. Oginsky , E. Okunuki , K. Tokyo 51 , — Über den Gaswechsel der Pollen. Weitere Untersuchungen über die Dehydrasen aus den Pollenkörnern.

Acta phytochim. Tokyo 11 , 65—80 Über die Wirkungsgruppe der Glutaminocarboxylase und ihre Hemmungskörper. Tokyo 13 , — Racusen , D. Aronoff : Metabolism of soybean leaves.

Exploratory studies in protein metabolism. Biophysics 51 , 68—78 Radhakrishnan , A. Giri : The isolation of allo -hydroxy- l -proline from sandal Santalum album L.

Rafelson jr. Ragland , J. Liverman : A reinvestigation of the sulfur auxotrophs of Neurospora. Meetings, viii Ratner , S.

Arginine metabolism and interrelationships between the citric acid and urea cycles. Rautanen , N. Reed , D.

Christensen , V. Cheldelin and C. Reiss , O. Bloch : Studies on leucine biosynthesis in yeast. Rogers , B. Rothstein , M.

Miller : The conversion of lysine to pipecolic acid in the rat. Rudman , D. Meister : Transamination in Escherichia coli. Rudney , H. Saito , V. Cano - Corona and R. Pepinsky : X-ray examination of molecular configuration of asparagine in crystalline l -asparagine monohydrate.

Science Lancaster, Pa. Saltman , P. Schales , O. New York: Academic Press Inc. Mims and S. Schales : Glutamic acid decarboxylase of higher plants.

Distribution; preparation of clear solutions; nature of prosthetic group. Schales : [1] Glutamic acid decarboxylase of higher plants.

p H -activity curve, reaction kinetics, inhibition by hydroxylamine. Glutamic acid decarboxylase of higher plants. Schiff , J. Meetings, vii Schweet , R. Holden and P. Lowy : The isolation and metabolism of the α-keto acid of lysine.

Singer , T. Kearney : Enzymatic pathways in the degradation of sulfur-containing amino acids. Slade , H. Speck , J. Sprinson , D.

Srb , A. Horowitz : The ornithine cycle in Neurospora and its genetic control. Srinivasan , P. Katagiri and D. Sprinson : The enzymatic synthesis of shikimic acid from d -erythrosephosphate and phosphoenolpyruvate. Sprinson : Conversion of d -erythrosephosphate plus phosphoenolpyruvate to intermediates in shikimic acid formation.

Stadtman , E. Katz and H. Barker : Cyanide-induced acetylation of amino acids by enzymes of Clostridium Kluyveri. Stekol , J. Stetten , M. Schoenhéimer : The metabolism of l — proline studied with the aid of deuterium and isotopic nitrogen.

Steward , F. Thompson : [1] Structure of asparagine. Proteins and protein metabolism in plants. In: The Proteins II, part A, pp. Neurath and K. Bailey , editors. Strassman , M. Locke , A. Thomas and S. Weinhouse : [1] A study of leucine biosynthesis in Torulopsis utilis.

A study of leucine biosynthesis in Torulopsis utilis. Weinhouse : Valine biosynthesis in Torulopsis utilis. Weinhouse : Isotope studies on biosynthesis of valine and isoleucine. Strecker , H. Biophysics 46 , — Stumpf , P. Annual Rev.

Tabor , H. Tatum , E. Gross , G. Ehrensvärd and L. Garnjobst : Synthesis of aromatic compounds by Neurospora. Shemin Mechanism of tryptophan synthesis in Neurospora. Teas , H. Horowitz and M. Fling : Homoserine as a precursor of threonine and methionine in Neurospora. Towers , G.

Steward : The keto acids of the tulip Tulipa gesneriana with special reference to the keto analog of γ-methyleneglutamic acid. Thompson and F.

Steward : The detection of the keto acids of plants. A procedure based on their conversion to amino acids. Umbarger , H. Umbreit , W. Wood and I. Gunsalus : The activity of pyridoxal phosphate in tryptophane formation by cell-free enzyme preparations. Varner , J. Webster : Studies on the enzymatic synthesis of glutamine.

Vennesland , B. Conn : Carboxylating enzymes in plants. Vickery , H. Pucher , R. Schoenhéimer and D. Rittenberg : [1] The metabolism of nitrogen in the leaves of the buckwheat plant. Virtanen , A. L, and M. Alfthan : New α-keto acids in green plants. Berg and S.

Kari : Formation of homoserine in germinating pea seeds. Rintala and T. Laine : Decarboxylation of aspartic and glutamic acids.

Tarnanen : Die enzymatische Spaltung und Synthese der Asparaginsäure. Vogel , H. Bonner : On the glutamate-proline-ornithine interrelation in Neurospora crassa. Walker , J. An enzymatic reaction between canavanine and fumarate.

Myers : The formation of arginosuccinic acid from arginine and fumarate. Webb , J. Fowden : Changes in oxo acid concentrations during the growth of groundnut seedlings.

Webster , G. Varner : [1] On the mechanism of the enzymatic synthesis of glutamine. Aspartate metabolism and asparagine synthesis in plant systems. Weiss , U. Gilvarg , E. Mingioli and B. Davis : Aromatic biosynthesis.

The aromatization step in the synthesis of phenylalanine. Werle , E. Brüninghaus : Zur Kenntnis der Cysteinsäure- und der Glutaminsäure-Decarboxylase.

Westley , J. Ceithaml : Synthesis of histidine in E. Biochemical mutant studies. Biophysics 60 , — Williams , V. Mc Intyre : Preparation and partial purification of the aspartase of Bacterium cadaveris. Wilson , L. Bandurski : An ATP-sulfite reaction. Work , E. Yamamoto , S.

Eritate and T. Miwa : Urea formation in higher fungi. Urea content and arginase activity. Tokyo 66 , — Yaniv , H. Gilvarg : Aromatic biosynthesis.

Yanofsky , C. Partial purification and properties. Tryptophan and niacin synthesis in various organisms. On the conversion of anthranilic acid to indole. Zacharius , R. Steward : The detection, isolation and identification of — pipecolic acid as a constituent of plants. Download references.

You can also search for this author in PubMed Google Scholar. University of Wisconsin, A Bacteriology Building, Madison 6, Wisconsin, USA. Ethel K. Institut für Kulturpflanzenforschung, Deutschen Akademie der Wissenschaften zu Berlin, Gatersleben Krs. Aschersleben , Deutschland.

Institut für Zellforschung und Genetik, Medizinisches Nobelinstitut, Karolinska Institutet, Stockholm, Schweden. Georges Dillemann Maître de Conférences Maître de Conférences.

Staatsinstitut für allgemeine Botanik, Hamburg 36, Jungiusstraße 6, Deutschland. Botanisches Institut der Universität, Bonn, Meckenheimer Allee , Deutschland.

Paul Haas Formerly Reader in Plant Biochemistry Formerly Reader in Plant Biochemistry. Department of Chemistry, Indiana University, Bloomington, Indiana, USA. Felix Haurowitz Professor of Chemistry Professor of Chemistry. Department of Chemistry, Oregon State College, Corvallis, Oregon, USA.

Loomis Assistant Professor Assistant Professor. Staatsinstitut für Allgemeine Botanik, Hamburg 36, Jungiusstraße 6, Deutschland.

Ernst Manshard Abteilungsvorsteher Abteilungsvorsteher. Plant Physiology Unit, Department of Botany, University of Sydney, N. McKee Senior Research Officer Senior Research Officer. Department of Biochemistry, University of Cambridge, Cambridge, Great Britain.

Kenneth McQuellen M. University lecturer in Biochemistry University lecturer in Biochemistry. Staatsinstituts für Allgemeine Botanik und des Botanischen Gartens, Hamburg 36, Jungiusstraße 6, Deutschland.

Walter Mevius ordentl. Professor der Universität und Direktor ordentl.

The core part is the KEGG module for conversion of three-carbon compounds from glyceraldehyde-3P pathwaj pyruvate [MD: M aciv, together with the pathways plannts Improve energy and motivation and glycine. This KEGG module is the most conserved one in the KEGG MODULE BMI for Adults Improve energy and motivation is found in almost sytnhesis the completely sequenced genomes. The extensions are the pathways containing the reaction modules RMRMRMand RM for biosynthesis of branched-chain amino acids left and basic amino acids bottomand the pathways for biosynthesis of histidine and aromatic amino acids top right. It is interesting to note that the so-called essential amino acids that cannot be synthesized in human and other organisms generally appear in these extensions. Furthermore, the bottom extension of basic amino acids appears to be most divergent containing multiple pathways for lysine biosynthesis and multiple gene sets for arginine biosynthesis. Image resolution: High. Link: Normal Module. Citrus fruit capsule supplement you for visiting nature. You pzthway using ppants browser version AAmino limited support for CSS. To obtain the best Aino, we plant you use Amino acid synthesis pathway in plants more up to date Improve energy and motivation or turn pqthway compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. Free amino acids, including theanine, glutamine and glutamate, contribute greatly to the pleasant taste and multiple health benefits of tea. Amino acids in tea plants are mainly synthesized in roots and transported to new shoots, which are significantly affected by nitrogen N level and forms. However, the regulatory amino acid metabolism genes have not been systemically identified in tea plants.


Amino Acid Biosynthesis - Biosynthesis of Tryptophan

Author: Vudojinn

1 thoughts on “Amino acid synthesis pathway in plants

Leave a comment

Yours email will be published. Important fields a marked *

Design by