Expression for Caffeine Biosynthesis and Related Enzymes in Camellia sinensis

2010 ◽  
Vol 65 (3-4) ◽  
pp. 245-256 ◽  
Author(s):  
Misako Kato ◽  
Naoko Kitao ◽  
Mariko Ishida ◽  
Hanayo Morimoto ◽  
Fumi Irino ◽  
...  

Caffeine (1,3,7-trimethylxanthine) is a purine alkaloid that is present in high concentrations in the tea plant Camellia sinensis. Caffeine synthase (CS, EC 2.1.1.160) catalyzes the S-adenosyl-L-methionine-dependent N-3- and N-1-methylation of the purine base to form caffeine, the last step in the purine alkaloid biosynthetic pathway. We studied the expression profile of the tea caffeine synthase (TCS) gene in developing leaves and flowers by means of northern blot analysis, and compared it with those of phenylalanine ammonia lyase (PAL, EC 4.3.1.5), chalcone synthase (CHS, EC 2.3.1.74), and S-adenosyl-L-methionine synthase (SAMS, EC 2.5.1.6). The amount of TCS transcripts was highest in young leaves and declined markedly during leaf development, whereas it remained constant throughout the development of the flower. Environmental stresses other than heavy metal stress and plant hormone treatments had no effect on the expression of TCS genes, unlike the other three genes. Drought stress suppressed TCS gene expression in leaves, and the expression pattern mirrored that of the dehydrin gene. The amounts of TCS transcripts increased slightly on supply of a nitrogen source. We discuss the regulation of TCS gene expression

2015 ◽  
Vol 10 (5) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Wei-Wei Deng ◽  
Min Li ◽  
Chen-Chen Gu ◽  
Da-Xiang Li ◽  
Lin-Long Ma ◽  
...  

Caffeine, a purine alkaloid, is a major secondary metabolite in tea leaves. The demand for low caffeine tea is increasing in recent years, especially for health reasons. We report a novel grafted tea material with low caffeine content. The grafted tea plant had Camellia sinensis as scions and C. oleifera as stocks. The content of purine alkaloids was determined in the leaves of one-year-old grafted tea plants by HPLC. We also characterized caffeine synthase (CS), a key enzyme involved in caffeine biosynthesis in tea plants, at the expression level. The expression patterns of CS were examined in grafted and control leaves by Western blot, using a self-prepared polyclonal antibody with high specificity and sensitivity. The expression of related genes ( TCS1, tea caffeine synthase gene, GenBank accession No. AB031280; sAMS, SAM synthetase gene, AJ277206; TIDH, IMP dehydrogenase gene, EU106658) in the caffeine biosynthetic pathway was investigated by qRT-PCR. HPLC showed that the caffeine content was only 38% as compared with the non-grafted tea leaves. Immunoblotting analysis showed that CS protein decreased by half in the leaves of grafted tea plants. qRT-PCR revealed no significant changes in the expression of two genes in the upstream pathway ( sAMS and TIDH), while the expression of TCS1 was greatly decreased (50%). Taken together, these data revealed that the low caffeine content in the grafted tea leaves is due to low TCS1 expression and CS protein accumulation.


2019 ◽  
Author(s):  
Shengrui Liu ◽  
Yanlin An ◽  
Wei Tong ◽  
Xiuju Qin ◽  
Lidia Samarina ◽  
...  

Abstract Single nucleotide polymorphisms (SNPs) and insertions/deletions (InDels) are the major genetic variations and are distributed extensively across the whole plant genome. However, few studies of these variations have been conducted in the long-lived perennial tea plant. In this study, we investigated the genome-wide genetic variation between Camellia sinensis var. sinensis ‘Shuchazao’ and Camellia sinensis var. assamica ‘Yunkang 10’, identified 7,511,731 SNPs and 255,218 InDels based on their whole genome sequences, and we subsequently analyzed their distinct types and distribution patterns. A total of 48 InDel markers that yielded polymorphic and unambiguous fragments were developed when screening six tea cultivars. These markers were further deployed on forty-six tea cultivars for transferability and genetic diversity analysis, exhibiting information with an average 4.02 of the number of alleles (Na) and 0.457 of polymorphism information content (PIC). The dendrogram showed that the phylogenetic relationships among these tea cultivars are highly consistent with their genetic backgrounds or original places. Interestingly, we observed that the catechin/caffeine contents between ‘Shuchazao’ and ‘Yunkang 10’ were significantly different, and a large number of SNPs/InDels were identified within catechin/caffeine biosynthesis-related genes. The identified genome-wide genetic variation and newly-developed InDel markers will provide a valuable resource for tea plant genetic and genomic studies, especially the SNPs/InDels within catechin/caffeine biosynthesis-related genes, which may serve as pivotal candidates for elucidating the molecular mechanism governing catechin/caffeine biosynthesis.


2017 ◽  
Author(s):  
Xiujuan He ◽  
Xuecheng Zhao ◽  
Liping Gao ◽  
Xingxing Shi ◽  
Xinlong Dai ◽  
...  

AbstractThere were several high concentrations of flavonoid components in tea leaves that present health benefits. A novel purple-leaf tea variety, ‘Mooma1’, was obtained from the natural hybrid population of Longjing 43 variety. The buds and young leaves of ‘Mooma1’ were displayed in bright red. HPLC and LC-MS analysis showed that anthocyanins and O-Glycosylated flavonols were remarkably accumulated in the leaves of ‘Mooma1’, while the total amount of catechins in purple-leaf leaves was slightly decreased compared with the control. A R2R3-MYB transcription factor (CsMYB6A) and a novel UGT gene (CsUGT72AM1), that were highly expressed in purple leaf were isolated and identified by transcriptome sequencing. The over-expression of transgenic tobacco confirmed that CsMYB6A can activate the expression of flavonoid-related structural genes, especially CHS and 3GT, controlling the accumulation of anthocyanins in the leaf of transgenic tobacco. Enzymatic assays in vitro confirmed that CsUGT72AM1 has catalytic activity as a flavonol 3-O-glucosyltransferase, and displayed broad substrate specificity. The results were useful for further elucidating the molecular mechanisms of the flavonoid metabolic fluxes in the tea plant.


BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Shengrui Liu ◽  
Yanlin An ◽  
Wei Tong ◽  
Xiuju Qin ◽  
Lidia Samarina ◽  
...  

Abstract Background Single nucleotide polymorphisms (SNPs) and insertions/deletions (InDels) are the major genetic variations and are distributed extensively across the whole plant genome. However, few studies of these variations have been conducted in the long-lived perennial tea plant. Results In this study, we investigated the genome-wide genetic variations between Camellia sinensis var. sinensis ‘Shuchazao’ and Camellia sinensis var. assamica ‘Yunkang 10’, identified 7,511,731 SNPs and 255,218 InDels based on their whole genome sequences, and we subsequently analyzed their distinct types and distribution patterns. A total of 48 InDel markers that yielded polymorphic and unambiguous fragments were developed when screening six tea cultivars. These markers were further deployed on 46 tea cultivars for transferability and genetic diversity analysis, exhibiting information with an average 4.02 of the number of alleles (Na) and 0.457 of polymorphism information content (PIC). The dendrogram showed that the phylogenetic relationships among these tea cultivars are highly consistent with their genetic backgrounds or original places. Interestingly, we observed that the catechin/caffeine contents between ‘Shuchazao’ and ‘Yunkang 10’ were significantly different, and a large number of SNPs/InDels were identified within catechin/caffeine biosynthesis-related genes. Conclusion The identified genome-wide genetic variations and newly-developed InDel markers will provide a valuable resource for tea plant genetic and genomic studies, especially the SNPs/InDels within catechin/caffeine biosynthesis-related genes, which may serve as pivotal candidates for elucidating the molecular mechanism governing catechin/caffeine biosynthesis.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Qing-Sheng Li ◽  
Xiao-Ming Lin ◽  
Ru-Ying Qiao ◽  
Xin-Qiang Zheng ◽  
Jian-Liang Lu ◽  
...  

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