GABA shunt contribution to flavonoid biosynthesis and metabolism in tea plants (Camellia sinensis)

2021 ◽  
Author(s):  
Jieren Liao ◽  
Qiang Shen ◽  
Ruiyang Li ◽  
Yu Cao ◽  
Yue Li ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Flavonoid Biosynthesis ◽  
Gaba Shunt ◽  
Tea Plants

scholarly journals GABA and Its Shunt’s Contributions to Flavonoid Biosynthesis and Metabolism in the Tea Plat (Camellia Sinensis)

2020 ◽  
Author(s):  
Jieren Liao ◽  
Yu Cao ◽  
Taiyu Ren ◽  
Qiang Shen ◽  
Yuhua Wang ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Camellia Sinensis ◽  
Growth Cycle ◽  
Tea Plant ◽  
Flavonoid Pathway ◽  
Signal Molecule ◽  
Polyamine Biosynthesis ◽  
Gaba Shunt ◽  
Flavonoid Metabolism ◽  
Tea Plants

Abstract Background: γ-Aminobutyric acid (GABA), a signal molecule, is regarded as the intersection of carbon and nitrogen metabolism, but its contributions to flavonoid metabolism in tea plants during the whole growth cycle remain unclear, and the correlation between the GABA shunt and flavonoid metabolism in tea plants is worth exploring. Secondary metabolites and their correlations with the taste qualities of tea plants (Camellia sinensis) during different seasons have been investigated.Results: Related secondary metabolites and transcript profiles of genes encoding enzymes in the GABA shunt, flavonoid pathway and polyamine biosynthesis were measured throughout the whole tea plant growth season and after exogenous GABA applications. In addition, levels of differentially expressed proteins were measured after treatment with or without exogenous GABA. The tea leaves showed the highest metabolite concentrations in spring. CsGAD, CsGABAT, CsSPMS, CsODC, CsF3H and CsCHS were found to be important genes in the GABA and anthocyanin network. Conclusion: GABA and anthocyanin concentrations showed a positive correlation, to some extent, and CsF3H and CsCHS played important roles in the GABA and anthocyanin network. Further studies should focus on exploring GABA and flavonoid metabolism through the transgenic engineering of tea plants.

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 The Protective Effect of Exogenous Putrescine in the Response of Tea Plants (Camellia sinensis) to Salt Stress

HortScience ◽  
2018 ◽  
Vol 53 (11) ◽  
pp. 1640-1646 ◽  
Author(s):  
Fei Xiong ◽  
Jieren Liao ◽  
Yuanchun Ma ◽  
Yuhua Wang ◽  
Wanping Fang ◽  
...  
Keyword(s):  
Salt Stress ◽  
Camellia Sinensis ◽  
Effective Means ◽  
Plant Performance ◽  
Photosynthetic Parameters ◽  
Activity Levels ◽  
Salinity Treatment ◽  
Ros Scavenging ◽  
Stress Levels ◽  
Tea Plants

Camellia sinensis cultivars were treated with 5 mm putrescine (Put) under a range of sodium chloride (NaCl) concentrations. Plant performance, as indicated by various indicators associated with plant growing condition such as photosynthetic parameters and polyamine (PA) contents, especially the content of Put, was improved by the treatment. The extent of both Na+ accumulation and K+ loss increased. The activity levels of the antioxidant enzymes related to salt stress, such as superoxide dismutase (SOD), peroxidase (POD), and catalase, were significantly altered with different salt stress levels and showed a decrease in the general trend. Besides, tea polyphenols, the tea quality indicator, increased during the salinity treatment but decreased when we applied Put. These findings suggest that treatment with Put might constitute an effective means for alleviating salinity stress–induced injury through its positive effect on photosynthetic efficiency and for controlling reactive oxygen species (ROS) scavenging ability under appropriate salt stress levels.

scholarly journals Molecular Identification and Characterization of Hydroxycinnamoyl Transferase in Tea Plants (Camellia sinensis L.)

2018 ◽  
Vol 19 (12) ◽  
pp. 3938 ◽  
Author(s):  
Chi-Hui Sun ◽  
Chin-Ying Yang ◽  
Jason Tzen
Keyword(s):  
Abiotic Stress ◽  
Amino Acid ◽  
Camellia Sinensis ◽  
Polymerase Chain Reaction Analysis ◽  
Coffea Canephora ◽  
Tea Plant ◽  
Amino Acid Sequences ◽  
Hibiscus Cannabinus ◽  
Expression Level ◽  
Tea Plants

Tea (Camellia sinensis L.) contains abundant secondary metabolites, which are regulated by numerous enzymes. Hydroxycinnamoyl transferase (HCT) is involved in the biosynthesis pathways of polyphenols and flavonoids, and it can catalyze the transfer of hydroxyconnamoyl coenzyme A to substrates such as quinate, flavanol glycoside, or anthocyanins, thus resulting in the production of chlorogenic acid or acylated flavonol glycoside. In this study, the CsHCT gene was cloned from the Chin-Shin Oolong tea plant, and its protein functions and characteristics were analyzed. The full-length cDNA of CsHCT contains 1311 base pairs and encodes 436 amino acid sequences. Amino acid sequence was highly conserved with other HCTs from Arabidopsis thaliana, Populus trichocarpa, Hibiscus cannabinus, and Coffea canephora. Quantitative real-time polymerase chain reaction analysis showed that CsHCT is highly expressed in the stem tissues of both tea plants and seedlings. The CsHCT expression level was relatively high at high altitudes. The abiotic stress experiment suggested that low temperature, drought, and high salinity induced CsHCT transcription. Furthermore, the results of hormone treatments indicated that abscisic acid (ABA) induced a considerable increase in the CsHCT expression level. This may be attributed to CsHCT involvement in abiotic stress and ABA signaling pathways.

scholarly journals Tolerance to water stress in boron-deficient tea (Camellia sinensis) plants

2012 ◽  
Vol 24 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Roghieh Hajiboland ◽  
Soodabe Bastani
Keyword(s):  
Water Stress ◽  
Camellia Sinensis ◽  
Stress Conditions ◽  
Assimilation Rate ◽  
Antioxidant Defence System ◽  
Young Leaves ◽  
Net Assimilation ◽  
Single Stress ◽  
Tea Plants ◽  
Lower Ratio

Tolerance to water stress in boron-deficient tea (Camellia sinensis) plantsThe effects of boron (B) deficiency and water stress were studied in tea plants (Camellia sinensis[L.] O. Kuntze) grown in growth chambers in perlite irrigated with a nutrient solution. Dry matter production was reduced significantly by both low B supply and water stress. Shoot-root translocation of B declined in water-stressed plants. In addition, the re-translocation of B was impaired under drought, which was reflected in a significantly lower ratio of B content of young to old leaves in both B-deficient and B-sufficient plants. Leaf photochemical parameters were negatively influenced by B deficiency and water stress in the old but not in the young leaves. Although B-deficient plants were more conservative in relation to water loss following elevated stomatal limitation, their water potential was lower than in B-sufficient plants irrespective of the watering regime. Under the combined effects of B deficiency and water stress, the reduction in the CO2assimilation rate was more prominent than that under a single stress factor. The reduction of the net assimilation rate (A) in B-deficient plants due to water stress and in water-stressed plants due to low B supply were not accompanied by significant changes in the stomatal conductance, suggesting an involvement of non-stomatal factors. The activity of antioxidant enzymes and proline content increased under B deficiency and water stress conditions. Our results suggested that, in young leaves that have been developed under water stress, an acclimation to water stress conditions occurred that was well reflected in their more stable photochemistry, water relations and an efficient antioxidant defence system compared with the older leaves.

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