scholarly journals Metabolic Characterization of the Anthocyanidin Reductase Pathway Involved in the Biosynthesis of Flavan-3-ols in Elite Shuchazao Tea (Camellia sinensis) Cultivar in the Field

Molecules ◽  
2017 ◽  
Vol 22 (12) ◽  
pp. 2241 ◽  
Author(s):  
Lei Zhao ◽  
Xiao-Lan Jiang ◽  
Yu-Mei Qian ◽  
De-Yu Xie ◽  
Li-Ping Gao ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Anthocyanidin Reductase

scholarly journals Biochemical characterization of specific Alanine Decarboxylase (AlaDC) and its ancestral enzyme Serine Decarboxylase (SDC) in tea plants (Camellia sinensis)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Peixian Bai ◽  
Liyuan Wang ◽  
Kang Wei ◽  
Li Ruan ◽  
Liyun Wu ◽  
...  
Keyword(s):  
Gene Duplication ◽  
Camellia Sinensis ◽  
Biochemical Characterization ◽  
Specific Activity ◽  
Protein Sequences ◽  
Biochemical Properties ◽  
High Similarity ◽  
New Gene ◽  
Tea Plants

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.

scholarly journals Biochemical and Functional Characterization of Anthocyanidin Reductase (ANR) from Mangifera indica L.

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2876 ◽  
Author(s):  
Lin Tan ◽  
Mei Wang ◽  
Youfa Kang ◽  
Farrukh Azeem ◽  
Zhaoxi Zhou ◽  
...  
Keyword(s):  
Enzyme Assay ◽  
Molecular Mechanisms ◽  
Mangifera Indica ◽  
Functional Characterization ◽  
Citrate Buffer ◽  
Anthocyanidin Reductase ◽  
High Amino Acid ◽  
Optimum Ph

Mango (Mangifera indica L.) is abundant in proanthocyanidins (PAs) that are important for human health and plant response to abiotic stresses. However, the molecular mechanisms involved in PA biosynthesis still need to be elucidated. Anthocyanidin reductase (ANR) catalyzes a key step in PA biosynthesis. In this study, three ANR cDNAs (MiANR1-1,1-2,1-3) were isolated from mango, and expressed in Escherichia coli. In vitro enzyme assay showed MiANR proteins convert cyanidin to their corresponding flavan-3-ols, such as (−)-catechin and (−)-epicatechin. Despite high amino acid similarity, the recombinant ANR proteins exhibited differences in enzyme kinetics and cosubstrate preference. MiANR1-2 and MiANR1-3 have the same optimum pH of 4.0 in citrate buffer, while the optimum pH for MiANR1-1 is pH 3.0 in phosphate buffer. MiANR1-1 does not use either NADPH or NADH as co-substrate while MiANR1-2/1-3 use only NADPH as co-substrate. MiANR1-2 has the highest Km and Vmax for cyanidin, followed by MiANR1-3 and MiANR1-1. The overexpression of MiANRs in ban mutant reconstructed the biosynthetic pathway of PAs in the seed coat. These data demonstrate MiANRs can form the ANR pathway, leading to the formation of two types of isomeric flavan-3-ols and PAs in mango.

Characterization of dihydroflavonol 4-reductase cDNA in tea [Camellia sinensis (L.) O. Kuntze]

2008 ◽  
Vol 3 (1) ◽  
pp. 95-101 ◽  
Author(s):  
Kashmir Singh ◽  
Sanjay Kumar ◽  
Sudesh Kumar Yadav ◽  
Paramvir Singh Ahuja
Keyword(s):  
Camellia Sinensis

Characterization of Volatile Components of Tea Flowers (Camellia sinensis) Growing in Kangra by GC/MS

2011 ◽  
Vol 6 (8) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Robin Joshi ◽  
Poonam ◽  
Rikki Saini ◽  
Shailja Guleria ◽  
Garikapati D. Kiran Babu ◽  
...  
Keyword(s):  
Supercritical Fluid ◽  
Camellia Sinensis ◽  
Methyl Palmitate ◽  
Headspace Analysis ◽  
Volatile Components ◽  
Linalool Oxide ◽  
Germacrene D ◽  
Simultaneous Distillation Extraction ◽  
Volatile Flavour

Volatile flavour components of tea flowers ( Camellia sinensis) were isolated by two methods viz. simultaneous distillation extraction (SDE), supercritical fluid extraction (SFE), analyzed by GC and GC/MS and compared with headspace analysis (HS). The composition of the volatile components extracted by the three methods differed considerably. In SFE, phenylethanol (14.7%), linalool (7.9%), ( E)-linalool oxide furanoid (3.5%), epoxy linalool (1.6%), geraniol (2.3%) and hotrienol (1.5%) were major components. m-Xylene (2.6%), ( E)-linalool oxide pyranoid (5.4%), p-myrcene (5.2%), α-cadinol (4.3%) and methyl palmitate (2.9%) were major compounds isolated by SDE. 3-hexenol (2.1%) ( E)-4,8-dimethyl-1,3,7-nonatriene (20.9%) and linalool (35.1%) are major components in headspace analysis. Acetophenone and pheromone germacrene D is detected in tea flowers by all the methods studied. Floral, fresh and fruity odour of tea flowers is retained by SFE as there is very little loss of heat sensitive volatiles in SFE. The flavour isolated from SFE has superior quality compared to SDE.

Isolation and characterization of highly polymorphic microsatellites in tea (Camellia sinensis)

2004 ◽  
Vol 4 (3) ◽  
pp. 324-326 ◽  
Author(s):  
SUSAN FREEMAN ◽  
JON WEST ◽  
CELIA JAMES ◽  
VINCE LEA ◽  
SEAN MAYES
Keyword(s):  
Camellia Sinensis ◽  
Isolation And Characterization ◽  
Polymorphic Microsatellites
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