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Li H, Song K, Zhang X, Wang D, Dong S, Liu Y, Yang L. Application of Multi-Perspectives in Tea Breeding and the Main Directions. Int J Mol Sci 2023; 24:12643. [PMID: 37628823 PMCID: PMC10454712 DOI: 10.3390/ijms241612643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 07/29/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
Tea plants are an economically important crop and conducting research on tea breeding contributes to enhancing the yield and quality of tea leaves as well as breeding traits that satisfy the requirements of the public. This study reviews the current status of tea plants germplasm resources and their utilization, which has provided genetic material for the application of multi-omics, including genomics and transcriptomics in breeding. Various molecular markers for breeding were designed based on multi-omics, and available approaches in the direction of high yield, quality and resistance in tea plants breeding are proposed. Additionally, future breeding of tea plants based on single-cellomics, pangenomics, plant-microbe interactions and epigenetics are proposed and provided as references. This study aims to provide inspiration and guidance for advancing the development of genetic breeding in tea plants, as well as providing implications for breeding research in other crops.
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Affiliation(s)
| | | | | | | | | | | | - Long Yang
- College of Plant Protection and Agricultural Big-Data Research Center, Shandong Agricultural University, Tai’an 271018, China
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2
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Chen Z, Lin S, Chen T, Han M, Yang T, Wang Y, Bao S, Shen Z, Wan X, Zhang Z. Haem Oxygenase 1 is a potential target for creating etiolated/albino tea plants ( Camellia sinensis) with high theanine accumulation. HORTICULTURE RESEARCH 2023; 10:uhac269. [PMID: 37533676 PMCID: PMC10390853 DOI: 10.1093/hr/uhac269] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/01/2022] [Indexed: 08/04/2023]
Abstract
Theanine content is highly correlated with sensory quality and health benefits of tea infusion. The tender shoots of etiolated and albino tea plants contain higher theanine than the normal green tea plants and are valuable materials for high quality green tea processing. However, why these etiolated or albino tea plants can highly accumulate theanine is largely unknown. In this study, we observed an Arabidopsis etiolated mutant hy1-100 (mutation in Haem Oxygenase 1, HO1) that accumulated higher levels of glutamine (an analog of theanine). We therefore identified CsHO1 in tea plants and found CsHO1 is conserved in amino acid sequences and subcellular localization with its homologs in other plants. Importantly, CsHO1 expression in the new shoots was much lower in an etiolated tea plants 'Huangkui' and an albino tea plant 'Huangshan Baicha' than that in normal green tea plants. The expression levels of CsHO1 were negatively correlated with theanine contents in these green, etiolated and albino shoots. Moreover, CsHO1 expression levels in various organs and different time points were also negatively correlated with theanine accumulation. The hy1-100 was hypersensitive to high levels of theanine and accumulated more theanine under theanine feeding, and these phenotypes were rescued by the expression of CsHO1 in this mutant. Transient knockdown CsHO1 expression in the new shoots of tea plant using antisense oligonucleotides (asODN) increased theanine accumulation. Collectively, these results demonstrated CsHO1 negatively regulates theanine accumulation in tea plants, and that low expression CsHO1 likely contributes to the theanine accumulation in etiolated/albino tea plants.
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Affiliation(s)
| | | | - Tingting Chen
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, 230036, China
| | - Mengxue Han
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, 230036, China
| | - Tianyuan Yang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, 230036, China
| | - Yan Wang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, 230036, China
| | - Shilai Bao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- School of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhougao Shen
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, 230036, China
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, 230036, China
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3
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Li J, Xiao Y, Zhou X, Liao Y, Wu S, Chen J, Qian J, Yan Y, Tang J, Zeng L. Characterizing the cultivar-specific mechanisms underlying the accumulation of quality-related metabolites in specific Chinese tea (Camellia sinensis) germplasms to diversify tea products. Food Res Int 2022; 161:111824. [DOI: 10.1016/j.foodres.2022.111824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 08/03/2022] [Accepted: 08/19/2022] [Indexed: 12/25/2022]
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4
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Guo J, Zhu B, Chen Y, Lin S, Qiao S, Ma F, Zhang S, Yang T, Chen Q, Liu L, Zhang Z, Wan X. Potential 'accelerator' and 'brake' regulation of theanine biosynthesis in tea plant ( Camellia sinensis). HORTICULTURE RESEARCH 2022; 9:uhac169. [PMID: 36324642 PMCID: PMC9614919 DOI: 10.1093/hr/uhac169] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 07/20/2022] [Indexed: 06/16/2023]
Affiliation(s)
| | | | - Ying Chen
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Shijia Lin
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Siming Qiao
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Fuli Ma
- College of Horticulture, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Shihua Zhang
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei 430072, China
| | - Tianyuan Yang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Qi Chen
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Linlin Liu
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
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5
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Lin S, Chen Z, Chen T, Deng W, Wan X, Zhang Z. Theanine metabolism and transport in tea plants ( Camellia sinensis L.): advances and perspectives. Crit Rev Biotechnol 2022; 43:327-341. [PMID: 35430936 DOI: 10.1080/07388551.2022.2036692] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Theanine, a tea plant-specific non-proteinogenic amino acid, is the most abundant free amino acid in tea leaves. It is also one of the most important quality components of tea because it endows the "umami" taste, relaxation-promoting, and many other health benefits of tea infusion. Its content in tea leaves is directly correlated with the quality and price of green tea. Theanine biosynthesis primarily occurs in roots and is transported to new shoots in tea plants. Recently, great advances have been made in theanine metabolism and transport in tea plants. Along with the deciphering of the genomic sequences of tea plants, new genes in theanine metabolic pathway were discovered and functionally characterized. Theanine transporters were identified and were characterized on the affinity for: theanine, substrate specificity, spatiotemporal expression, and the role in theanine root-to-shoot transport. The mechanisms underlying the regulation of theanine accumulation by: cultivars, seasons, nutrients, and environmental factors are also being rapidly uncovered. Transcription factors were identified to be critical regulators of theanine biosynthesis. In this review, we summarize the progresses in theanine: biosynthesis, catabolism, and transport processes. We also discuss the future studies on theanine in tea plants, and application of the knowledge to crops to synthesize theanine to improve the health-promoting quality of non-tea crops.
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Affiliation(s)
- Shijia Lin
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China
| | - Ziping Chen
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China
| | - Tingting Chen
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China
| | - Weiwei Deng
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China
| | - Zhaoliang Zhang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China
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6
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She G, Yu S, Li Z, Peng A, Li P, Li Y, Chang M, Liu L, Chen Q, Shi C, Sun J, Zhao J, Wan X. Characterization of CsTSI in the Biosynthesis of Theanine in Tea Plants ( Camellia sinensis). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:826-836. [PMID: 35029385 DOI: 10.1021/acs.jafc.1c04816] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Theanine is a unique major amino acid in tea plants responsible for umami taste and mental health benefits of tea. However, theanine biosynthesis and physiological role in tea plants are not fully understood. Here, we demonstrate that tea plant theanine synthetase is encoded by a glutamine synthetase gene CsTSI. The expression pattern of CsTSI is closely correlated with theanine and glutamine levels in various tissues. CsTSI transcripts were accumulated in root tip epidermal cells, pericycle and procambial cells, where CsTSI presents as a cytosolic protein. Ectopic expression of the gene in Arabidopsis led to greater glutamine and theanine production than controls when fed with ethylamine (EA). RNAi knockdown or overexpression of CsTSI in tea plant hairy roots reduced or enhanced theanine and glutamine contents, respectively, compared with controls. The CsTSI recombinant enzymes used glutamate as an acceptor and ammonium or EA as a donor to synthesize glutamine and theanine, respectively. CsTSI expression in tea roots responded to nitrogen supply and deprivation and was correlated with theanine contents. This study provides fresh insights into the molecular basis for the biosynthesis of theanine, which may facilitate the breeding of high-theanine tea plants for improving the nutritional benefit of tea.
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Affiliation(s)
- Guangbiao She
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Shuwei Yu
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Zhenguo Li
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Anqi Peng
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Penghui Li
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Yingying Li
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Manman Chang
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Linlin Liu
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Qi Chen
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Chengying Shi
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Jun Sun
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Jian Zhao
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, China
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7
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Fu X, Liao Y, Cheng S, Deng R, Yang Z. Stable Isotope-Labeled Precursor Tracing Reveals that l-Alanine is Converted to l-Theanine via l-Glutamate not Ethylamine in Tea Plants In Vivo. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:15354-15361. [PMID: 34904439 DOI: 10.1021/acs.jafc.1c06660] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Tea plants (Camellia sinensis) specifically produce l-theanine, which contributes to tea function and taste. Ethylamine is a limiting factor differentiating l-theanine accumulation between tea and other plants. Ethylamine has long been assumed to be derived from l-alanine in tea. In this study, the l-alanine content in tea root cells was mainly located in vacuoles and mitochondria using a nonaqueous fractionation technique, while alanine decarboxylase in tea (CsADC) was located in the cytoplasm. Although CsADC was able to catalyze l-alanine decarboxylation to produce ethylamine in vitro, it may not provide the same enzyme activity in tea plants. Stable isotope-labeled precursor tracing in tea plants discovered that l-alanine is not a direct precursor of ethylamine but a precursor of l-glutamate, which is involved in l-theanine biosynthesis in tea. Cortex with epidermis from root tissue was the main location of ethylamine. In summary, l-alanine is converted to l-theanine via l-glutamate not ethylamine in tea plants in vivo.
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Affiliation(s)
- Xiumin Fu
- Guangdong Provincial Key Laboratory of Applied Botany & Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
| | - Yinyin Liao
- Guangdong Provincial Key Laboratory of Applied Botany & Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
| | - Sihua Cheng
- Guangdong Provincial Key Laboratory of Applied Botany & Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
| | - Rufang Deng
- Guangdong Provincial Key Laboratory of Applied Botany & Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
| | - Ziyin Yang
- Guangdong Provincial Key Laboratory of Applied Botany & Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
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8
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Xie N, Zhang C, Zhou P, Gao X, Wang M, Tian S, Lu C, Wang K, Shen C. Transcriptomic analyses reveal variegation-induced metabolic changes leading to high L-theanine levels in albino sectors of variegated tea (Camellia sinensis). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 169:29-39. [PMID: 34749269 DOI: 10.1016/j.plaphy.2021.10.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/17/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
Camellia sinensis cv. 'Yanling Huayecha' (YHC) is an albino-green chimaeric tea mutant with stable genetic traits. Here, we analysed the cell ultrastructure, photosynthetic pigments, amino acids, and transcriptomes of the albino, mosaic, and green zones of YHC. Well-organized thylakoids were found in chloroplasts in mesophyll cells of the green zone but not the albino zone. The albino zone of the leaves contained almost no photosynthetic pigment. However, the levels of total amino acids and theanine were higher in the albino zone than in the mosaic and green zones. A transcriptomic analysis showed that carbon metabolism, nitrogen metabolism and amino acid biosynthesis showed differences among the different zones. Metabolite and transcriptomic analyses revealed that (1) downregulation of CsPPOX1 and damage to thylakoids in the albino zone may block chlorophyll synthesis; (2) downregulation of CsLHCB6, CsFdC2 and CsSCY1 influences chloroplast biogenesis and thylakoid membrane formation, which may contribute to the appearance of variegated tea leaves; and (3) tea plant variegation disrupts the balance between carbon and nitrogen metabolism and promotes the accumulation of amino acids, and upregulation of CsTSⅠ and CsAlaDC may enhance L-theanine synthesis. In summary, our study provides a theoretical basis and valuable insights for elucidating the molecular mechanisms and promoting the economic utilization of variegation in tea.
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Affiliation(s)
- Nianci Xie
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Chenyu Zhang
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Pinqian Zhou
- Tea Research Institute of Hunan Academy of Agricultural Sciences, Changsha, Hunan, 410125, China
| | - Xizhi Gao
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Minghan Wang
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Shuanghong Tian
- Xiangxi Academy of Agricultural Sciences, Jishou, Hunan, 416000, China
| | - Cui Lu
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Kunbo Wang
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, 410128, China.
| | - Chengwen Shen
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, 410128, China.
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9
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Zhu B, Guo J, Dong C, Li F, Qiao S, Lin S, Yang T, Wu Y, Bao S, Lucas WJ, Zhang Z. CsAlaDC and CsTSI work coordinately to determine theanine biosynthesis in tea plants (Camellia sinensis L.) and confer high levels of theanine accumulation in a non-tea plant. PLANT BIOTECHNOLOGY JOURNAL 2021; 19:2395-2397. [PMID: 34626137 PMCID: PMC8633503 DOI: 10.1111/pbi.13722] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 09/17/2021] [Accepted: 10/02/2021] [Indexed: 05/13/2023]
Affiliation(s)
- Biying Zhu
- State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefeiAnhuiChina
| | - Jiayi Guo
- State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefeiAnhuiChina
| | - Chunxia Dong
- State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefeiAnhuiChina
| | - Fang Li
- State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefeiAnhuiChina
- College of HorticultureNanjing Agricultural UniversityNanjingChina
| | - Siming Qiao
- State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefeiAnhuiChina
| | - Shijia Lin
- State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefeiAnhuiChina
| | - Tianyuan Yang
- State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefeiAnhuiChina
| | - Yingling Wu
- State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefeiAnhuiChina
| | - Shilai Bao
- State Key Laboratory of Molecular Developmental BiologyInstitute of Genetics and Developmental BiologyChinese Academy of SciencesBeijingChina
- School of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - William J. Lucas
- Department of Plant BiologyCollege of Biological SciencesUniversity of CaliforniaDavisCAUSA
| | - Zhaoliang Zhang
- State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefeiAnhuiChina
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10
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Yu Y, Kou X, Gao R, Chen X, Zhao Z, Mei H, Li J, Jeyaraj A, Thangaraj K, Periakaruppan R, Zhuang J, Chen X, Arkorful E, Li X. Glutamine Synthetases Play a Vital Role in High Accumulation of Theanine in Tender Shoots of Albino Tea Germplasm "Huabai 1". JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:13904-13915. [PMID: 34775761 DOI: 10.1021/acs.jafc.1c04567] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Theanine (N-ethyl-γ-l-glutamine) is a special nonprotein amino acid that contributes to the umami taste and health function of tea. Although recent studies on tea breeding have focused on albino tea because of its umami taste, a factor of higher theanine concentration, the mechanism of biosynthesis of l-theanine is still unclear. In this study, four glutamine synthetase genes (CsGSs) were obtained and functionally characterized by overexpressing them in Arabidopsis. The enzyme activities of the purified CsGS proteins from Escherichia coli were detected. The results showed that CsGSs have a dual function in the synthesis of glutamine and theanine in vivo and in vitro. Interestingly, l-theanine was abundantly synthesized in the tender shoots of "Huabai 1". In the white tender shoots, the cytosol CsGS1.2 might exhibit increased expression to compensate for decreasing levels of chloroplast CsGS2, which plays a vital role in high accumulation of theanine in "Huabai 1". In addition, CsGS2 was most likely the key l-theanine synthases in green tissues of tea. The present findings will provide basis for and considerably broaden the scope of understanding the function of CsGSs and the mechanism of l-theanine accumulation in the tender shoots of "Huabai 1", and will be useful for breeding and screening tea with high l-theanine content.
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Affiliation(s)
- Ying Yu
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Xiaobing Kou
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Ruoshi Gao
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Xuefei Chen
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Zhen Zhao
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Huiling Mei
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jianjie Li
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Anburaj Jeyaraj
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Kuberan Thangaraj
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Rajiv Periakaruppan
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Jing Zhuang
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Xuan Chen
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Emmanuel Arkorful
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara 630-0192, Japan
| | - Xinghui Li
- College of Horticulture, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
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Chen Y, Liu S, Ferreira JFDS, Xiao L, Gu M, Luo Y, Zhang T, Zhang X, Liu Z, Huang J, Tian N. Development and Application of a Fast Gas Chromatographic Method Offer New Insights into l-theanine Production Regulation in Camellia sinensis L. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:11142-11150. [PMID: 34514782 DOI: 10.1021/acs.jafc.1c04093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Tea is the most consumed beverage worldwide, and l-theanine in tea leaves significantly affects their flavor and market quality. We have developed and validated a fast and reliable gas chromatographic method with flame ionization detection (GC-FID) to quantify l-theanine after its extraction from Camellia sinensis (tea plant) and derivatization. The procedure was completed in 40 min, from extraction to chromatographic analysis, with a recovery rate of more than 93% and allowing a high sample throughput. The GC-FID intraday precision was within 0.57-2.28%, while the interday precision ranged from 1.57 to 13.48%. The intraday accuracy ranged from -6.84 to 5.26%, while the interday accuracy ranged from -1.08 to 3.12%. The limit of detection was 2.28 μg/mL, and the limit of quantification was 6.47 μg/mL. The GC-FID method was validated by high-performance liquid chromatography with UV detection (HPLC-UV) and was used to investigate the biosynthesis and regulation of l-theanine in tea plants. We found that plants fed with ethylamine significantly increased l-theanine concentrations in roots, while exogenous supplementation of glutamic acid, carbamide, and glutamine did not significantly affect the l-theanine level in roots. Our results also indicated that roots were not indispensable for the biosynthesis of l-theanine, which was detected in undifferentiated embryonic calluses in concentrations (g/100 g dry weight) as high as in leaves of whole plants (1.67 and 1.57%, respectively) and without any exogenous theanine precursor supplementation.
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Affiliation(s)
- Yanni Chen
- Department of Tea Science, College of Horticulture, Hunan Agricultural University, Changsha 410128, China
| | - Shuoqian Liu
- Department of Tea Science, College of Horticulture, Hunan Agricultural University, Changsha 410128, China
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
| | - Jorge Freire da Silva Ferreira
- United States Salinity Laboratory, United States Department of Agriculture-Agricultural Research Service, Riverside, California 92507, United States
| | - Lizheng Xiao
- Department of Tea Science, College of Horticulture, Hunan Agricultural University, Changsha 410128, China
| | - Meiyi Gu
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
| | - Yiping Luo
- Department of Tea Science, College of Horticulture, Hunan Agricultural University, Changsha 410128, China
| | - Tiantian Zhang
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
| | - Xiangqin Zhang
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
| | - Zhonghua Liu
- Department of Tea Science, College of Horticulture, Hunan Agricultural University, Changsha 410128, China
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
| | - Jianan Huang
- Department of Tea Science, College of Horticulture, Hunan Agricultural University, Changsha 410128, China
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
| | - Na Tian
- Department of Tea Science, College of Horticulture, Hunan Agricultural University, Changsha 410128, China
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12
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Wang Y, Cheng X, Yang T, Su Y, Lin S, Zhang S, Zhang Z. Nitrogen-Regulated Theanine and Flavonoid Biosynthesis in Tea Plant Roots: Protein-Level Regulation Revealed by Multiomics Analyses. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:10002-10016. [PMID: 34406741 DOI: 10.1021/acs.jafc.1c02589] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Theanine and flavonoids (especially proanthocyanidins) are the most important and abundant secondary metabolites synthesized in the roots of tea plants. Nitrogen promotes theanine and represses flavonoid biosynthesis in tea plant roots, but the underlying mechanism is still elusive. Here, we analyzed theanine and flavonoid metabolism in tea plant roots under nitrogen deficiency and explored the regulatory mechanism using proteome and ubiquitylome profiling together with transcriptome data. Differentially expressed proteins responsive to nitrogen deficiency were identified and found to be enriched in flavonoid, nitrogen, and amino acid metabolism pathways. The proteins responding to nitrogen deficiency at the transcriptional level, translational level, and both transcriptional and translational levels were classified. Nitrogen-deficiency-responsive and ubiquitinated proteins were further identified. Our results showed that most genes encoding enzymes in the theanine synthesis pathway, such as CsAlaDC, CsGDH, and CsGOGATs, were repressed by nitrogen deficiency at transcriptional and/or protein level(s). While a large number of enzymes in flavonoid metabolism were upregulated at the transcriptional and/or translational level(s). Importantly, the ubiquitylomic analysis identified important proteins, especially the hub enzymes in theanine and flavonoid biosynthesis, such as CsAlaDC, CsTSI, CsGS, CsPAL, and CsCHS, modified by ubiquitination. This study provided novel insights into the regulation of theanine and flavonoid biosynthesis and will contribute to future studies on the post-translational regulation of secondary metabolism in tea plants.
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Affiliation(s)
- Yan Wang
- State Key Laboratory of Tea Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, People's Republic of China
| | - Xunmin Cheng
- State Key Laboratory of Tea Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, People's Republic of China
| | - Tianyuan Yang
- State Key Laboratory of Tea Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, People's Republic of China
| | - Yanlei Su
- State Key Laboratory of Tea Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, People's Republic of China
| | - Shijia Lin
- State Key Laboratory of Tea Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, People's Republic of China
| | - Shupei Zhang
- State Key Laboratory of Tea Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, People's Republic of China
| | - Zhaoliang Zhang
- State Key Laboratory of Tea Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, People's Republic of China
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14
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Production of l-Theanine by Escherichia coli in the Absence of Supplemental Ethylamine. Appl Environ Microbiol 2021; 87:AEM.00031-21. [PMID: 33741612 DOI: 10.1128/aem.00031-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 03/09/2021] [Indexed: 11/20/2022] Open
Abstract
l-Theanine is a nonproteinogenic amino acid present almost exclusively in tea plants and is beneficial for human health. For industrial production, l-theanine is enzymatically or chemically synthesized from glutamine/glutamate (or a glutamine/glutamate derivative) and ethylamine. Ethylamine is extremely flammable and toxic, which complicates and increases the cost of operational procedures. To solve these problems, we developed an artificial biosynthetic pathway to produce l-theanine in the absence of supplemental ethylamine. For this purpose, we identified and selected a novel transaminase (NCBI:protein accession number AAN70747) from Pseudomonas putida KT2440, which catalyzes the transamination of acetaldehyde to produce ethylamine, as well as γ-glutamylmethylamide synthetase (NCBI:protein accession number AAY37316) from Pseudomonas syringae pv. syringae B728a, which catalyzes the condensation of l-glutamate and ethylamine to produce l-theanine. Expressing these genes in Escherichia coli W3110S3GK and enhancing the production capacity of acetaldehyde and l-alanine achieved successful production of l-theanine without ethylamine supplementation. Furthermore, the deletion of ggt, which encodes γ-glutamyltranspeptidase (EC 2.3.2.2), achieved large-scale production of l-theanine by attenuating its decomposition. We show that an alanine decarboxylase-utilizing pathway represents a promising route for the fermentative production of l-theanine. Our study reports efficient methods to produce l-theanine in the absence of supplemental ethylamine.IMPORTANCE l-Theanine is widely used in food additives and dietary supplements. Industrial production of l-theanine uses the toxic and highly flammable precursor ethylamine, raising production costs. In this study, we used Escherichia coli to engineer two biosynthetic pathways that produce l-theanine from glucose and ammonia in the absence of supplemental ethylamine. This study establishes a foundation for safely and economically producing l-theanine.
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Yang T, Xie Y, Lu X, Yan X, Wang Y, Ma J, Cheng X, Lin S, Bao S, Wan X, Lucas WJ, Zhang Z. Shading Promoted Theanine Biosynthesis in the Roots and Allocation in the Shoots of the Tea Plant ( Camellia sinensis L.) Cultivar Shuchazao. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:4795-4803. [PMID: 33861578 DOI: 10.1021/acs.jafc.1c00641] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Shading was thought as an effective approach to increase theanine in harvested tea shoots. Previous studies offered conflicting findings, perhaps since the integration of theanine metabolism and transport in different tissues was not considered. Theanine is synthesized primarily in the roots and is then transported, via the vascular system, to new vegetative tissues. Here, we found that theanine increased in the stem, was reduced in the leaf, and remained stable in the roots, under shading conditions. Notably, in tea roots, shading significantly increased ethylamine and activated the theanine biosynthesis pathway and theanine transporter genes. Furthermore, shading significantly increased the expression of theanine transporter genes, CsAAP2/4/5/8, in the stem, while decreasing the expression of CsAAP1/2/4/5/6 in the leaf, in accordance with shading effects on theanine levels in these tissues. These findings reveal that shading of tea plants promotes theanine biosynthesis and allocation in different tissues, processes which appear to involve the theanine biosynthesis pathway enzymes and AAP family of theanine transporters.
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Affiliation(s)
- Tianyuan Yang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Yunxia Xie
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Xin Lu
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Xiaomei Yan
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Yan Wang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Jingzhen Ma
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Xunmin Cheng
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Shijia Lin
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Shilai Bao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - William J Lucas
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, California 95616, United States
| | - Zhaoliang Zhang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
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Zhang Y, Li P, She G, Xu Y, Peng A, Wan X, Zhao J. Molecular Basis of the Distinct Metabolic Features in Shoot Tips and Roots of Tea Plants ( Camellia sinensis): Characterization of MYB Regulator for Root Theanine Synthesis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:3415-3429. [PMID: 33719427 DOI: 10.1021/acs.jafc.0c07572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The physiological and metabolic differences between shoot tips and roots of tea plants are significant, and understanding them is required for improvement of tea quality and plant growth. A high-quality full-length transcriptome sequencing on tea plant roots and shoot tips by PacBio SMRT technology was done to gain a further understanding. Approximately 160699 and 166120 full-length transcripts were recovered in roots and shoots, respectively, including 31232 and 41068 novel isoforms and 16960 and 26029 alternative splicing (AS) isoforms. These supported 21699 full-length reads and 31232 and 41068 novel transcripts from root and shoot, respectively, including 1679 long noncoding RNAs (lncRNAs) and 2772 fusion transcripts, which significantly upgrade the Camellia sinensis genome annotation. The respective 6475 and 6981 transcripts in roots and shoots differ in 3'-untranslated regions. Meanwhile, extensive analyses of novel transcripts, ASs, and lncRNAs also revealed a large number of ASs and lincRNAs closely related to the regulation of characteristic secondary metabolites including catechins, theanine, and caffeine. Finally, a root-specific CsMYB6 was characterized to regulate theanine biosynthesis by genetic and molecular analyses. CsMYB6 directly bound to and activate the promoter of theanine synthetase gene (CsTSI). The study lays a foundation for the further investigation of metabolic genomics and regulation in tea plants.
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Affiliation(s)
- Yanrui Zhang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Penghui Li
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Guangbiao She
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Yujie Xu
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Anqi Peng
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Jian Zhao
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, People's Republic of China
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Feng J, Yang C, Zhao Z, Xu J, Li J, Li P. Application of Cell-Free Protein Synthesis System for the Biosynthesis of l-Theanine. ACS Synth Biol 2021; 10:620-631. [PMID: 33719397 DOI: 10.1021/acssynbio.0c00618] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
l-Theanine, as an active component of the leaves of the tea plant, possesses many health benefits and broad applications. Chemical synthesis of l-theanine is possible; however, this method generates chiral compounds and needs further isolation of the pure l-isoform. Heterologous biosynthesis is an alternative strategy, but one main limitation is the toxicity of the substrate ethylamine on microbial host cells. In this study, we introduced a cell-free protein synthesis (CFPS) system for l-theanine production. The CFPS expressed l-theanine synthetase 2 from Camellia sinensis (CsTS2) could produce l-theanine at a concentration of 11.31 μM after 32 h of the synthesis reaction. In addition, three isozymes from microorganisms were expressed in CFPS for l-theanine biosynthesis. The γ-glutamylcysteine synthetase from Escherichia coli could produce l-theanine at the highest concentration of 302.96 μM after 24 h of reaction. Furthermore, CFPS was used to validate a hypothetical two-step l-theanine biosynthetic pathway consisting of the l-alanine decarboxylase from C. sinensis (CsAD) and multiple l-theanine synthases. Among them, the combination of CsAD and the l-glutamine synthetase from Pseudomonas taetrolens (PtGS) could synthesize l-theanine at the highest concentration of 13.42 μM. Then, we constructed an engineered E. coli strain overexpressed CsAD and PtGS to further confirm the l-theanine biosynthesis ability in living cells. This engineered E. coli strain could convert l-alanine and l-glutamate in the medium to l-theanine at a concentration of 3.82 mM after 72 h of fermentation. Taken together, these results demonstrated that the CFPS system can be used to produce the l-theanine through the two-step l-theanine biosynthesis pathway, indicating the potential application of CFPS for the biosynthesis of other active compounds.
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Affiliation(s)
- Junchen Feng
- Research Center for Translational Medicine at Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Chen Yang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhehao Zhao
- Research Center for Translational Medicine at Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Junjian Xu
- Research Center for Translational Medicine at Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Jian Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Ping Li
- Research Center for Translational Medicine at Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
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18
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Bai P, Wang L, Wei K, Ruan L, Wu L, He M, Ni D, Cheng H. Biochemical characterization of specific Alanine Decarboxylase (AlaDC) and its ancestral enzyme Serine Decarboxylase (SDC) in tea plants (Camellia sinensis). BMC Biotechnol 2021; 21:17. [PMID: 33648478 PMCID: PMC7923638 DOI: 10.1186/s12896-021-00674-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022] Open
Abstract
Background Alanine decarboxylase (AlaDC), specifically present in tea plants, is crucial for theanine biosynthesis. Serine decarboxylase (SDC), found in many plants, is a protein most closely related to AlaDC. To investigate whether the new gene AlaDC originate from gene SDC and to determine the biochemical properties of the two proteins from Camellia sinensis, the sequences of CsAlaDC and CsSDC were analyzed and the two proteins were over-expressed, purified, and characterized. Results The results showed that exon-intron structures of AlaDC and SDC were quite similar and the protein sequences, encoded by the two genes, shared a high similarity of 85.1%, revealing that new gene AlaDC originated from SDC by gene duplication. CsAlaDC and CsSDC catalyzed the decarboxylation of alanine and serine, respectively. CsAlaDC and CsSDC exhibited the optimal activities at 45 °C (pH 8.0) and 40 °C (pH 7.0), respectively. CsAlaDC was stable under 30 °C (pH 7.0) and CsSDC was stable under 40 °C (pH 6.0–8.0). The activities of the two enzymes were greatly enhanced by the presence of pyridoxal-5′-phosphate. The specific activity of CsSDC (30,488 IU/mg) was 8.8-fold higher than that of CsAlaDC (3467 IU/mg). Conclusions Comparing to CsAlaDC, its ancestral enzyme CsSDC exhibited a higher specific activity and a better thermal and pH stability, indicating that CsSDC acquired the optimized function after a longer evolutionary period. The biochemical properties of CsAlaDC might offer reference for theanine industrial production. Supplementary Information The online version contains supplementary material available at 10.1186/s12896-021-00674-x.
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Affiliation(s)
- Peixian Bai
- National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, 310008, Zhejiang, China.,College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Liyuan Wang
- National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, 310008, Zhejiang, China
| | - Kang Wei
- National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, 310008, Zhejiang, China
| | - Li Ruan
- National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, 310008, Zhejiang, China
| | - Liyun Wu
- National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, 310008, Zhejiang, China
| | - Mengdi He
- National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, 310008, Zhejiang, China
| | - Dejiang Ni
- College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
| | - Hao Cheng
- National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, 310008, Zhejiang, China.
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Liao Y, Zhou X, Zeng L. How does tea ( Camellia sinensis) produce specialized metabolites which determine its unique quality and function: a review. Crit Rev Food Sci Nutr 2021; 62:3751-3767. [PMID: 33401945 DOI: 10.1080/10408398.2020.1868970] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Tea (Camellia sinensis) is both a plant and a foodstuff. Many bioactive compounds, which are present in the final tea product and related to its quality or functional properties, are produced during the tea manufacturing process. However, the characteristic secondary metabolites, which give tea its unique qualities and are beneficial to human health, are produced mainly in the leaves during the process of plant growth. Therefore, it is important to understand how tea leaves produce these specialized metabolites. In this review, we first compare the common metabolites and specialized metabolites in tea, coffee, cocoa, and grape and discuss the occurrence of characteristic secondary metabolites in tea. Progress in research into the formation of these characteristic secondary metabolites in tea is summarized, including establishing a biological database and genetic transformation system, and the biosynthesis of characteristic secondary metabolites. Finally, speculation on future research into the characteristic secondary metabolites of tea is provided from the viewpoints of the origin, resources, cultivation, and processing of tea. This review provides an important reference for future research on the specialized metabolites of tea in terms of its characteristics.
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Affiliation(s)
- Yinyin Liao
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaochen Zhou
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Lanting Zeng
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
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20
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Chen Z, Lin S, Li J, Chen T, Gu Q, Yang T, Zhang Z. Theanine Improves Salt Stress Tolerance via Modulating Redox Homeostasis in Tea Plants ( Camellia sinensis L.). FRONTIERS IN PLANT SCIENCE 2021; 12:770398. [PMID: 34721495 PMCID: PMC8554060 DOI: 10.3389/fpls.2021.770398] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 09/27/2021] [Indexed: 05/11/2023]
Abstract
Theanine, a unique non-proteinogenic amino acid, is one of the most abundant secondary metabolites in tea. Its content largely determines green tea quality and price. However, its physiological roles in tea plants remain largely unknown. Here, we showed that salt stress significantly increased the accumulation of glutamate, glutamine, alanine, proline, and γ-aminobutyric acid, as well as theanine, in the new shoots of tea plants. We further found that salt stress induced the expression of theanine biosynthetic genes, including CsGOGATs, CsAlaDC, and CsTSI, suggested that salt stress induced theanine biosynthesis. Importantly, applying theanine to the new shoots significantly enhanced the salt stress tolerance. Similar effects were also found in a model plant Arabidopsis. Notably, exogenous theanine application increased the antioxidant activity of the shoots under salt stress, suggested by reduced the reactive oxygen species accumulation and lipid peroxidation, as well as by the increased SOD, CAT, and APX activities and expression of the corresponding genes. Finally, genetic evidence supported that catalase-mediated antioxidant scavenging pathway is required for theanine-induced salt stress tolerance. Taken together, this study suggested that salt stress induces theanine biosynthesize in tea plants to enhance the salt stress tolerance through a CAT-dependent redox homeostasis pathway.
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Affiliation(s)
- Ziping Chen
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Shijia Lin
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Juan Li
- Biotechnology Center, Anhui Agricultural University, Hefei, China
| | - Tingting Chen
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Quan Gu
- School of Biology, Food and Environment, Hefei University, Hefei, China
| | - Tianyuan Yang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Zhaoliang Zhang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
- *Correspondence: Zhaoliang Zhang,
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21
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Wang J, Chen W, Wang H, Li Y, Wang B, Zhang L, Wan X, Li M. Transcription factor CsDOF regulates glutamine metabolism in tea plants (Camellia sinensis). PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 302:110720. [PMID: 33288026 DOI: 10.1016/j.plantsci.2020.110720] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/09/2020] [Accepted: 10/12/2020] [Indexed: 06/12/2023]
Abstract
Glutamine plays a critical role in ammonium assimilation, and contributes substantially to the taste and nutritional quality of tea. To date, little research has been done on glutamine synthesis in tea plants. Here, a zinc finger protein CsDOF and a glutamine synthetase (GS)-encoding gene CsGS2 from tea plant (Camellia sinensis cv 'Shuchazao') were characterized, and their role in glutamine biosynthesis was determined using transient suppression assays in tea leaves and overexpression in Arabidopsis thaliana. The expression patterns of CsDOF and CsGS2, the GS activity and the glutamine content of photosynthetic tissues (leaf and bud) were significantly induced by shade. Suppressing the expression of CsDOF resulted in downregulated expression of CsGS2 and reduction of the leaf glutamine content. Moreover, in CsDOF-silenced plants, the expression of CsDOF and the glutamine content under shade treatment were higher than in natural light. The glutamine content and CsGS2 transcript level were also decreased in tea leaves when CsGS2 was suppressed, while they were higher under shade treatment than in natural light in CsGS2-silenced plants. In addition, the glutamine content and GS2 transcript level were increased when CsDOF and CsGS2 was overexpressed in Arabidopsis thaliana, respectively. In binding analyses, CsDOF directly bound to an AAAG motif in the promoter of CsGS2, and promotes its activity. The study shed new light on the molecular mechanism by which CsDOF activates CsGS2 gene expression and contributes to glutamine biosynthesis in tea plants.
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Affiliation(s)
- Jinhe Wang
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Wenzhen Chen
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Hanyue Wang
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Yuanda Li
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Biao Wang
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Lixia Zhang
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui, 230036, China.
| | - Min Li
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China.
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Fan X, Zhang T, Ji Y, Li J, Long K, Yuan Y, Li Y, Xu Q, Chen N, Xie X. Pathway engineering of Escherichia coli for one-step fermentative production of L-theanine from sugars and ethylamine. Metab Eng Commun 2020; 11:e00151. [PMID: 33251110 PMCID: PMC7677707 DOI: 10.1016/j.mec.2020.e00151] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/26/2020] [Accepted: 11/03/2020] [Indexed: 01/08/2023] Open
Abstract
L-theanine is the most abundant free amino acid in tea that offers various favorable physiological and pharmacological effects. Bacterial enzyme of γ-glutamylmethylamide synthetase (GMAS) can catalyze the synthesis of theanine from glutamate, ethylamine and ATP, but the manufacturing cost is uncompetitive due to the expensive substrates and complex processes. In this study, we described pathway engineering of wild-type Escherichia coli for one-step fermentative production of theanine from sugars and ethylamine. First, the synthetic pathway of theanine was conducted by heterologous introduction of a novel GMAS from Paracoccus aminovorans. A xylose-induced T7 RNA polymerase-PT7 promoter system was used to enhance and control gmas gene expression. Next, the precursor glutamate pool was increased by overexpression of native citrate synthase and introduction of glutamate dehydrogenase from Corynebacterium glutamicum. Then, in order to push more carbon flux towards theanine synthesis, the tricarboxylic acid cycle was interrupted and pyruvate carboxylase from C. glutamicum was introduced as a bypath supplying oxaloacetate from pyruvate. Finally, an energy-conserving phosphoenolpyruvate carboxykinase from Mannheimia succiniciproducens was introduced to increase ATP yield for theanine synthesis. After optimizing the addition time and concentration of ethylamine hydrochloride in the fed-batch fermentation, the recombinant strain TH11 produced 70.6 g/L theanine in a 5-L bioreactor with a yield and productivity of 0.42 g/g glucose and 2.72 g/L/h, respectively. To our knowledge, this is the first report regarding the pathway engineering of E. coli for fermentative production of theanine. The high production capacity of recombinant strain, combined with the easy processes, will hold attractive industrial application potential for the future. γ-Glutamylmethylamide synthetase from P. aminovorans showed high ligation activity. Xylose-induced T7 RNA polymerase-PT7 promoter system was used to control gene expression. TCA cycle was rewired to push more carbon flux toward theanine synthesis. Ethylamine feeding strategy was optimized to balance cell growth and theanine production.
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Affiliation(s)
- Xiaoguang Fan
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science & Technology, Tianjin, 300457, PR China.,College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Tong Zhang
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Yuanqing Ji
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Jie Li
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Keyi Long
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Yue Yuan
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Yanjun Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science & Technology, Tianjin, 300457, PR China.,College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Qingyang Xu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science & Technology, Tianjin, 300457, PR China.,College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Ning Chen
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science & Technology, Tianjin, 300457, PR China.,College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Xixian Xie
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science & Technology, Tianjin, 300457, PR China.,College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
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23
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Fu X, Cheng S, Liao Y, Xu X, Wang X, Hao X, Xu P, Dong F, Yang Z. Characterization of l-Theanine Hydrolase in Vitro and Subcellular Distribution of Its Specific Product Ethylamine in Tea ( Camellia sinensis). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:10842-10851. [PMID: 32866009 DOI: 10.1021/acs.jafc.0c01796] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
l-Theanine has a significant role in the taste of tea (Camellia sinensis) infusions. Our previous research indicated that the lower l-theanine metabolism in ethylamine and l-glutamate is a key factor that explains the higher content of l-theanine in albino tea with yellow or white leaves, compared with that of normal tea with green leaves. However, the specific genes encoding l-theanine hydrolase in tea remains unknown. In this study, CsPDX2.1 was cloned together with the homologous Arabidopsis PDX2 gene and the recombinant protein was shown to catalyze l-theanine hydrolysis into ethylamine and l-glutamate in vitro. There were higher CsPDX2.1 transcript levels in leaf tissue and lower transcripts in the types of albino (yellow leaf) teas compared with green controls. The subcellular location of ethylamine in tea leaves was shown to be in the mitochondria and peroxisome using a nonaqueous fractionation method. This study identified the l-theanine hydrolase gene and subcellular distribution of ethylamine in tea leaves, which improves our understanding of the l-theanine metabolism and the mechanism of differential accumulation of l-theanine among tea varieties.
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Affiliation(s)
- Xiumin Fu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
| | - Sihua Cheng
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China
| | - Yinyin Liao
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China
| | - Xinlan Xu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
| | - Xinchao Wang
- National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China
| | - Xinyuan Hao
- National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China
| | - Ping Xu
- Department of Tea Science, Zhejiang University, No. 388 Yuhangtang Road, Hangzhou 310058, China
| | - Fang Dong
- Guangdong Food and Drug Vocational College, No. 321 Longdongbei Road, Tianhe District, Guangzhou 510520, China
| | - Ziyin Yang
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, No. 723 Xingke Road, Tianhe District, Guangzhou 510650, China
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24
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Yamashita H, Fukuda Y, Yonezawa S, Morita A, Ikka T. Tissue ionome response to rhizosphere pH and aluminum in tea plants ( Camellia sinensis L.), a species adapted to acidic soils. PLANT-ENVIRONMENT INTERACTIONS (HOBOKEN, N.J.) 2020; 1:152-164. [PMID: 37283727 PMCID: PMC10168086 DOI: 10.1002/pei3.10028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/06/2020] [Accepted: 07/23/2020] [Indexed: 06/08/2023]
Abstract
The growth of tea plants (Camellia sinensis L.) is promoted by the presence of aluminum (Al), a beneficial element under acidic conditions, but the influence of rhizosphere pH on this interaction is not known. To understand the mechanisms underlying the adaptation to acidic rhizosphere conditions, we evaluated ionome profiles and the effect of pH on tea growth in hydroponic culture. The optimum pH for tea growth was around pH 4.2, and growth was inferior under a pH less than 3.8 or higher than 5.0. Under the optimum pH growth and Al accumulation were markedly stimulated by Al treatment. Al content and accumulation in new and mature leaves and new roots (the predominant tissues that accumulate minerals in tea plants) gradually declined with decrease in pH, especially in new roots. Ionome profiles drastically altered Al treatment, but changes were more pronounced in new roots than in new or mature leaves and did not depend on pH. Although the uptake of most cationic minerals in new roots was decreased by Al treatment, cationic mineral contents in new and mature leaves were not decreased by Al. In contrast to other plant species, the content and accumulation of manganese, despite it being a cationic nutrient, were significantly increased by Al treatment. These results indicated that one role of Al as a beneficial element was to maintain the shoot nutrient status by effectively utilizing Al-limited elements in the roots.
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Affiliation(s)
- Hiroto Yamashita
- Faculty of AgricultureShizuoka UniversityOhyaShizuokaJapan
- United Graduate School of Agricultural ScienceGifu UniversityYanagito, GifuJapan
| | - Yusuke Fukuda
- Faculty of AgricultureShizuoka UniversityOhyaShizuokaJapan
| | | | - Akio Morita
- Faculty of AgricultureShizuoka UniversityOhyaShizuokaJapan
| | - Takashi Ikka
- Faculty of AgricultureShizuoka UniversityOhyaShizuokaJapan
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25
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Joshi V, Joshi M, Penalosa A. Comparative analysis of tissue-specific transcriptomic responses to nitrogen stress in spinach (Spinacia oleracea). PLoS One 2020; 15:e0232011. [PMID: 32374731 PMCID: PMC7202632 DOI: 10.1371/journal.pone.0232011] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 04/05/2020] [Indexed: 12/11/2022] Open
Abstract
Nitrogen (N) is critical to the growth and productivity of crops. To understand the molecular mechanisms influenced by N stress, we used RNA-Sequencing (RNA-Seq) to analyze differentially expressed genes (DEGs) in root and leaf tissues of spinach. N stress negatively influenced photosynthesis, biomass accumulation, amino acid profiles, and partitioning of N across tissues. RNA-seq analysis revealed that N stress caused most transcriptomic changes in roots, identifying 1,346 DEGs. High-affinity nitrate transporters (NRT2.1, NRT2.5) and glutamine amidotransferase (GAT1) genes were strongly induced in roots in response to N deplete and replete conditions, respectively. GO and KEGG analyses revealed that the functions associated with metabolic pathways and nutrient reservoir activity were enriched due to N stress. Whereas KEGG pathway enrichment analysis indicated the upregulation of DEGs associated with DNA replication, pyrimidine, and purine metabolism in the presence of high N in leaf tissue. A subset of transcription factors comprising bHLH, MYB, WRKY, and AP2/ERF family members was over-represented in both tissues in response to N perturbation. Interesting DEGs associated with N uptake, amino acid metabolism, hormonal pathway, carbon metabolism, along with transcription factors, were highlighted. The results provide valuable information about the underlying molecular processes in response to N stress in spinach and; could serve as a resource for functional analysis of candidate genes/pathways and enhancement of nitrogen use efficiency.
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Affiliation(s)
- Vijay Joshi
- Texas A&M AgriLife Research and Extension Center, Uvalde, Texas, United States of America
- Department of Horticultural Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Madhumita Joshi
- Texas A&M AgriLife Research and Extension Center, Uvalde, Texas, United States of America
| | - Arianne Penalosa
- College of Science, University of Texas, Arlington, Texas, United States of America
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26
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Zhao J, Li P, Xia T, Wan X. Exploring plant metabolic genomics: chemical diversity, metabolic complexity in the biosynthesis and transport of specialized metabolites with the tea plant as a model. Crit Rev Biotechnol 2020; 40:667-688. [PMID: 32321331 DOI: 10.1080/07388551.2020.1752617] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The diversity and complexity of secondary metabolites in tea plants contribute substantially to the popularity of tea, by determining tea flavors and their numerous health benefits. The most significant characteristics of tea plants are that they concentrate the complex plant secondary metabolites into one leaf: flavonoids, alkaloids, theanine, volatiles, and saponins. Many fundamental questions regarding tea plant secondary metabolism remain unanswered. This includes how tea plants accumulate high levels of monomeric galloylated catechins, unlike the polymerized flavan-3-ols in most other plants, as well as how they are evolved to selectively synthesize theanine and caffeine, and how tea plants properly transport and store these cytotoxic products and then reuse them in defense. Tea plants coordinate many metabolic pathways that simultaneously take place in young tea leaves in response to both developmental and environmental cues. With the available genome sequences of tea plants and high-throughput metabolomic tools as great platforms, it is of particular interest to launch metabolic genomics studies using tea plants as a model system. Plant metabolic genomics are to investigate all aspects of plant secondary metabolism at the genetic, genome, and molecular levels. This includes plant domestication and adaptation, divergence and convergence of secondary metaboloic pathways. The biosynthesis, transport, storage, and transcriptional regulation mechanisms of all metabolites are of core interest in the plant as a whole. This review highlights relevant contexts of metabolic genomics, outstanding questions, and strategies for answering them, with aim to guide future research for genetic improvement of nutrition quality for healthier plant foods.
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Affiliation(s)
- Jian Zhao
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Penghui Li
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Tao Xia
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
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27
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Zhang G, Yang J, Cui D, Zhao D, Li Y, Wan X, Zhao J. Transcriptome and Metabolic Profiling Unveiled Roles of Peroxidases in Theaflavin Production in Black Tea Processing and Determination of Tea Processing Suitability. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:3528-3538. [PMID: 32129069 DOI: 10.1021/acs.jafc.9b07737] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Theaflavins (TFs) are generated by endogenous polyphenol oxidase (PPO)- and peroxidase (POD)-catalyzed catechins oxidation during black tea processing, which needs to be well-controlled to obtain a proper TFs/thearubigins (TRs) ratio for better quality. Not all leaves from any tea plant cultivars or varieties are suitable for making high-quality black teas, regardless of the processing techniques. The mechanisms underlying TFs formation and the main factors determining the tea leaf processing suitability are not fully understood. We here integrated transcriptome and metabolite profiling of tea leaves to unveil how enzymes or metabolites in leaves are changed during black tea processing. The information enabled us to identify several PPO and POD genes potentially involved in tea processing for TF production. We characterized a POD gene, whose recombinant enzyme showed TF creation activity. The capacity for POD-catalyzed TF production could be used as a molecular marker for breeding tea plant varieties suitable for high-quality black tea production.
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Affiliation(s)
- Gaoyang Zhang
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science and Technology, Anhui Agricultural University, 130 West Changjiang Road, Hefei 230036, China
| | - Jihong Yang
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science and Technology, Anhui Agricultural University, 130 West Changjiang Road, Hefei 230036, China
| | - Dandan Cui
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science and Technology, Anhui Agricultural University, 130 West Changjiang Road, Hefei 230036, China
| | - Dandan Zhao
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science and Technology, Anhui Agricultural University, 130 West Changjiang Road, Hefei 230036, China
| | - Yingying Li
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science and Technology, Anhui Agricultural University, 130 West Changjiang Road, Hefei 230036, China
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science and Technology, Anhui Agricultural University, 130 West Changjiang Road, Hefei 230036, China
| | - Jian Zhao
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Science and Technology, Anhui Agricultural University, 130 West Changjiang Road, Hefei 230036, China
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28
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Efficient fermentative production of L-theanine by Corynebacterium glutamicum. Appl Microbiol Biotechnol 2019; 104:119-130. [PMID: 31776607 DOI: 10.1007/s00253-019-10255-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/01/2019] [Accepted: 11/12/2019] [Indexed: 01/01/2023]
Abstract
L-Theanine is a unique non-protein amino acid found in tea plants that has been shown to possess numerous functional properties relevant to food science and human nutrition. L-Theanine has been commercially developed as a valuable additive for use in food and beverages, and its market is expected to expand substantially if the production cost can be lowered. Although the enzymatic approach holds considerable potential for use in L-theanine production, demand exists for developing more tractable methods (than those currently available) that can be implemented under mild conditions and will reduce operational procedures and cost. Here, we sought to engineer fermentative production of L-theanine in Corynebacterium glutamicum, an industrially safe host. For L-theanine synthesis, we used γ-glutamylmethylamide synthetase (GMAS), which catalyzes the ATP-dependent ligation of L-glutamate and ethylamine. First, distinct GMASs were expressed in C. glutamicum wild-type ATCC 13032 strain and GDK-9, an L-glutamate overproducing strain, to produce L-theanine upon ethylamine addition to the hosts. Second, the L-glutamate exporter in host cells was disrupted, which markedly increased the L-theanine titer in GDK-9 cells and almost eliminated the accumulation of L-glutamate in the culture medium. Third, a chromosomally gmasMm-integrated L-alanine producer was constructed and used, attempting to synthesize ethylamine endogenously by expressing plant-derived L-serine/L-alanine decarboxylases; however, these enzymes showed no L-alanine decarboxylase activity under our experimental conditions. The optimal engineered strain that we ultimately created produced ~ 42 g/L L-theanine, with a yield of 19.6%, in a 5-L fermentor. This is the first report of fermentative production of L-theanine achieved using ethylamine supplementation.
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29
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Sun J, Chang M, Li H, Zhang Z, Chen Q, Chen Y, Yao Y, Pan A, Shi C, Wang C, Zhao J, Wan X. Endophytic Bacteria as Contributors to Theanine Production in Camellia sinensis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:10685-10693. [PMID: 31479251 DOI: 10.1021/acs.jafc.9b03946] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Theanine is the most abundant non-protein amino acid in Camellia sinensis, but it is not known how a tea plant accumulates such high levels of theanine. The endophyte isolated from in vitro grown plantlets of C. sinensis cultivars was identified as Luteibacter spp., showing strong biocatalytic activity for converting both glutamine and ethylamine to theanine. Theanine was secreted outside of the bacteria. The endophyte isolated from in vitro plantlets of Camellia oleifera cultivar was identified as Bacillus safensis and did not convert glutamine and ethylamine to theanine. Enzymatic assays in vitro indicated that γ-glutamyltranspeptidases rCsEGGTs from the endophyte Luteibacter strains converted glutamine and ethylamine to theanine at higher rates than rCsGGTs from C. sinensis. This is the first report on theanine biosynthesis by an endophyte from C. sinensis, which provides a new pathway to explore the mechanism of theanine biosynthesis in C. sinensis and the interactions between an endophyte and tea plants.
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