Characterization of <scp>l</scp>-Theanine Hydrolase <i>in Vitro</i> and Subcellular Distribution of Its Specific Product Ethylamine in Tea (<i>Camellia sinensis</i>)

Fu, Xiumin; Cheng, Sihua; Liao, Yinyin; Xu, Xinlan; Wang, Xinchao; Hao, Xinyuan; Xu, Ping; Dong, Fang; Yang, Ziyin

doi:10.1021/acs.jafc.0c01796

Cited by 31 publications

(31 citation statements)

References 49 publications

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“…In tea shoot tissue, L-theanine biosynthesis occurred mainly in the cytosol and chloroplasts, and CsGS1.1 and CsGS2 most likely encode the key L-theanine synthases. CsPDX2.1 was a key enzyme that catalyzes L-theanine hydrolysis into ethylamine and glutamate, and the hydrolysis occurred mainly in the mitochondria and peroxisome [25,49]. In the study, the trend in expression of genes involved in L-theanine metabolism with increasing N application was not consistent with its accumulation in the tea leaves (Table 3 and Figure 2), which might be the result of differences in L-theanine synthesis among different organs and tea cultivars [49,54].…”

Section: Effect Of Long-term Nitrogen Application In Promoting Amino mentioning

confidence: 78%

“…To explore how N fertilizer affects L-theanine formation in fresh tea leaves, genes for L-theanine synthesis, including L-theanine synthase (CsTS1) and L-glutamine synthases (CsGSs), and degradation (pyridoxal 5′-phosphate synthase subunit, CsPDX) were selected for quantitative real-time PCR (qRT-PCR) [25,26]. As shown in Figure 2, the expression of CsTS1, CsGS1.1, and CsGS1.3 was lower in the N fertilizer treatments, and the expression of CsGS2 and CsGS1.2 was not significantly different among the four treatments.…”

Section: Effects Of Long-term Nitrogen Application On the Formation Omentioning

confidence: 99%

“…The synthesis of L-theanine in tea plants has been a hot topic in the study of N assimilation and absorption. To date, several important enzymes involved in the L-theanine metabolism pathway have been isolated and identified, such as L-theanine synthase, L-glutamine synthase, and L-theanine hydrolase [25,49,50]. However, the functions of related genes have not yet been proved definitively in transgenic tea plants.…”

Section: Effect Of Long-term Nitrogen Application In Promoting Amino mentioning

confidence: 99%

“…L-Theanine, L-glutamine, and L-glutamic acid were detected using an ultra-performance liquid chromatography/quadrupole time-of-flight (UPLC−QTOF-MS) system (Waters, Milford, MA, USA) as described previously [25]. Metabolites were separated on a HSS T3 column (1.8 μm, 100 mm × 2.1 mm; Waters, Milford, MA, USA) at 40 °C, with two elution binary gradients at a flow rate of 0.25 mL/min.…”

Section: Analyses Of Free Amino Acids In Tea Samplesmentioning

confidence: 99%

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Effects of Long-Term Nitrogen Fertilization on the Formation of Metabolites Related to Tea Quality in Subtropical China

Chen

Wang

et al. 2021

Metabolites

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As a main agronomic intervention in tea cultivation, nitrogen (N) application is useful to improve tea yield and quality. However, the effects of N application on the formation of tea quality-related metabolites have not been fully studied, especially in long-term field trials. In this study, a 10-year field experiment was conducted to investigate the effect of long-term N application treatments on tea quality-related metabolites, their precursors, and related gene expression. Long-term N application up-regulated the expression of key genes for chlorophyll synthesis and promoted its synthesis, thus increasing tea yield. It also significantly increased the contents of total free amino acids, especially l-theanine, in fresh tea leaves, while decreasing the catechin content, which is conducive to enhancing tea liquor freshness. However, long-term N application significantly reduced the contents of benzyl alcohol and 2-phenylethanol in fresh tea leaves, and also reduced (E)-nerolidol and indole in withered leaves, which were not conducive to the formation of floral and fruity aroma compounds. In general, an appropriate amount of N fertilizer (225 kg/hm2) balanced tea yield and quality. These results not only provide essential information on how N application affects tea quality, but also provide detailed experimental data for field fertilization.

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Section: Effect Of Long-term Nitrogen Application In Promoting Amino mentioning

confidence: 78%

Section: Effects Of Long-term Nitrogen Application On the Formation Omentioning

confidence: 99%

Section: Effect Of Long-term Nitrogen Application In Promoting Amino mentioning

confidence: 99%

Section: Analyses Of Free Amino Acids In Tea Samplesmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Long-Term Nitrogen Fertilization on the Formation of Metabolites Related to Tea Quality in Subtropical China

Chen

Wang

et al. 2021

Metabolites

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“…Some of housekeeping genes, such as the actin (ACT) gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, eukaryotic translation initiation factor (eIF) gene, TATA-box binding protein (TBP) gene, and ubiquitin-conjugating enzyme (UBC) gene, have been identi ed as reliable reference genes in plants [22,23,25]. In the expression experiments of C. sinensis, housekeeping genes, especially ACT gene, were the most frequently used reference genes [16,17,20,26]. Suitable reference genes in C. sinensis have been screened and evaluated under biotic and abiotic stress, biotic and abiotic stresses, tissue development, and hormone treatment [27][28][29][30][31].…”

mentioning

confidence: 99%

Evaluation and selection of suitable qRT-PCR reference genes for light responses in tea plant (Camellia sinensis)

Wang

Liu

Tang

et al. 2021

Scientia Horticulturae

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Background: Tea plant (Camellia sinensis) is an important woody economic crop used for processing leaf-type beverages. Tea has been proved to be bene cial to human health because it is rich in tea polyphenols and other active ingredients. Numerous studies have shown that light is a necessary environmental condition to control the growth and metabolism of C. sinensis. Gene expression experiments are always performed to explore the transcriptional regulation mechanism of plants widely based on the technique of quantitative real time polymerase chain reaction (qRT-PCR). The screening and application of reference genes are necessary for the normalization of gene expression under speci c conditions. However, the reference genes for systematic analysis of light-induced transcription mechanisms are still not available in C. sinensis.Results: In this research, we identi ed actin family genes that are always used as reference genes with high frequency and without distinction for various expression experiments in C. sinensis. Six pairs of distinctive primers (corresponding to CsACT1, CsACT2, CsACT(3-4), CsACT(5-6), CsACT(7-8), and CsACT(9-10) genes) were designed to evaluate their expression stability in response to light quality (LQ), light intensity (LI), and photoperiod (PD). Simultaneously, six other family members (CsUBC1, CsCLATHRIN1, CsGAPDH, CsTBP, CsTIP41, and CseIF-4α) of C. sinensis commonly used as reference genes were also investigated. The stability rankings of gene expression were calculated by the statistical algorithms of geNorm, BestKeeper, NormFinder, and RefFinder softwares.Conclusions: CsACT(5-6), CsTIP41, and CsACT(3-4) were the most stable genes for light quality (LQ), light intensity (LI), and photoperiod (PD) treatments, respectively. This study provides a basis for the selection of reference genes for future research on the transcription mechanism of light response in C. sinensis. Moreover, the analysis of actin family members of C. sinensis will help to understand the individual transcription mechanism of housekeeping family. BackgroundQuantitative real time polymerase chain reaction (qRT-PCR) is a universal technique to analyze gene expression because of its high sensitivity, good repeatability, and fast speed [1,2]. In the process of using qRT-PCR to analyze gene expression, the purity and concentration of the sample cannot be absolutely guaranteed that may cause experimental errors [2,3]. In order to make the results more accurate, it is necessary to use the reference gene as a reference to standardize the expression level of the target gene and correct the discrepancy of transcription e ciency and cDNA usage [2,4]. Stable expression is the basis for selection of reference genes because of the selection of unstable reference genes will lead to test deviation. Some genes necessary for maintaining basic cell functions have been found in plants, called housekeeping genes, whose expression levels are less affected by environmental conditions and developmental stages [5,6]. The housekeeping genes o...

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Chemical constituents of green teas processed from albino tea cultivars with white and yellow shoots

Yang

Zhou²,

Liu³

et al. 2022

Food Chemistry: Molecular Sciences

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Characterization of l-Theanine Hydrolase in Vitro and Subcellular Distribution of Its Specific Product Ethylamine in Tea (Camellia sinensis)

Cited by 31 publications

References 49 publications

Effects of Long-Term Nitrogen Fertilization on the Formation of Metabolites Related to Tea Quality in Subtropical China

Effects of Long-Term Nitrogen Fertilization on the Formation of Metabolites Related to Tea Quality in Subtropical China

Evaluation and selection of suitable qRT-PCR reference genes for light responses in tea plant (Camellia sinensis)

Chemical constituents of green teas processed from albino tea cultivars with white and yellow shoots

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