Understanding different regulatory mechanisms of proteinaceous and non-proteinaceous amino acid formation in tea (<i>Camellia sinensis</i>) provides new insights into the safe and effective alteration of tea flavor and function

Yu, Zhenming; Yang, Ziyin

doi:10.1080/10408398.2018.1552245

Cited by 188 publications

(115 citation statements)

References 128 publications

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“…Furthermore, tea plants synthesize a myriad of aroma compounds (e.g., volatile terpenes, fatty acid derivatives, and phenylpropanoids/benzenoids) in response to biotic and abiotic stresses 21 . Last but not the least, caffeine 22 and non-proteinaceous amino acid L-theanine 23 , 24 , which is particularly abundant in tea plants, also are key contributors to tea quality. An important goal for tea improvement is to breed for the increases of specific target metabolites and/or downregulation of some other target metabolites 25 .…”

Section: Introductionmentioning

confidence: 99%

Metabolite signatures of diverse Camellia sinensis tea populations

et al. 2020

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The tea plant (Camellia sinensis) presents an excellent system to study evolution and diversification of the numerous classes, types and variable contents of specialized metabolites. Here, we investigate the relationship among C. sinensis phylogenetic groups and specialized metabolites using transcriptomic and metabolomic data on the fresh leaves collected from 136 representative tea accessions in China. We obtain 925,854 high-quality single-nucleotide polymorphisms (SNPs) enabling the refined grouping of the sampled tea accessions into five major clades. Untargeted metabolomic analyses detect 129 and 199 annotated metabolites that are differentially accumulated in different tea groups in positive and negative ionization modes, respectively. Each phylogenetic group contains signature metabolites. In particular, CSA tea accessions are featured with high accumulation of diverse classes of flavonoid compounds, such as flavanols, flavonol mono-/di-glycosides, proanthocyanidin dimers, and phenolic acids. Our results provide insights into the genetic and metabolite diversity and are useful for accelerated tea plant breeding.

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Section: Introductionmentioning

confidence: 99%

Metabolite signatures of diverse Camellia sinensis tea populations

et al. 2020

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“…Specifically, theanine originally accounted for more than 50% of the total amino acids content was found to decrease over time, and this variation was consistent with previous report (Chatterjee, Chatterjee, & Bandyopadhyay, ). Theanine contributes to the sweet taste (Ekborg‐Ott, Taylor, & Armstrong, ; Yu, & Yang, ) as well as the umami (Juneja, Chu, Okubo, Nagato, & Yokogoshi, ; Narukawa, Toda, Nakagita, Hayashi, & Misaka, ) taste of tea infusions. Thus, free amino acids can be divided into sweet amino acids (gly, ser, ala, pro, thr, met, and theanine), bitter amino acids (arg, his, ile, leu, phe, lys, tyr, and val), and umami amino acids (asp, glu, and theanine) according to the different taste characteristics of amino acids (Scharbert & Hofmann, ; Zhang et al, ), and the contents of these amino acids were investigated (Figure ).…”

Section: Resultsmentioning

confidence: 99%

Distinct variation in taste quality of Congou black tea during a single spring season

Huang

Zhao

et al. 2020

Food Science & Nutrition

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The quality of Congou black tea fluctuates greatly with the changing seasons.However, variations in the taste quality of Congou black tea manufactured during a single spring season are far from clear. Here, we analyzed the taste quality of HuangJinCha (HJC) Congou black tea using sensory evaluation and found the taste quality of black tea manufactured in the early spring was better than that manufactured in the late spring. Principal component analysis (PCA) and cluster analysis for the data from the electronic tongue confirmed the variation and revealed that April 4 may be the critical time point at which variations in taste quality become apparent.The contents of tea polyphenols (TP), total catechins (TC), total flavones, (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG), and gallic acid (GA) showed increasing trends, whereas total amino acids (TAA) declined over time. Moreover, the variations in total amino acids (r = 0.846) and total flavones (r = -0.858) were highly significantly correlated with the average taste quality score (p < .01), suggesting these compounds were the primary factors responsible for the fluctuation in taste quality of Congou black tea processed during a single spring season. K E Y W O R D Sblack tea, electronic tongue, sensory evaluation, spring season, taste quality

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“…In general, the contents of secondary metabolites significantly affect the quality of tea products 54 . Among the various metabolic products, amino acids greatly contribute to the quality of green tea.…”

Section: Discussionmentioning

confidence: 99%

“…It is important to achieve a comprehensive understanding of the underlying molecular basis of www.nature.com/scientificreports www.nature.com/scientificreports/ 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][57] .…”

Section: Discussionmentioning

confidence: 99%

Transcriptional regulation of amino acid metabolism in response to nitrogen deficiency and nitrogen forms in tea plant root (Camellia sinensis L.)

Yang

Tai

et al. 2020

Sci Rep

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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. 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.(Ser), glycine (Gly) and cysteine (Cys) synthesis. In tea plant, Thea is synthesized from Glu and ethylamine (EA) by theanine synthetase (TS) 14 . EA is likely produced from alanine under the catalysis of alanine decarboxylase 15 .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 16 .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 17 . Here, the accumulation of an amino acid inhibits the transcription or the activities of the enzymes in its biosynthesis pathway [18][19][20] . Expression of feedback-insensitive form of enzymes resulted in higher levels of the corresponding amino acids 17,21 . The central role of amino acid catabolism is to adjust the amino acid pool size, especially under stress conditions 12 . Some regulatory enzymes in amino acid metabolism have been ident...

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Understanding different regulatory mechanisms of proteinaceous and non-proteinaceous amino acid formation in tea (Camellia sinensis) provides new insights into the safe and effective alteration of tea flavor and function

Cited by 188 publications

References 128 publications

Metabolite signatures of diverse Camellia sinensis tea populations

Metabolite signatures of diverse Camellia sinensis tea populations

Distinct variation in taste quality of Congou black tea during a single spring season

Transcriptional regulation of amino acid metabolism in response to nitrogen deficiency and nitrogen forms in tea plant root (Camellia sinensis L.)

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