Summary
Tea is the world's widely consumed nonalcohol beverage with essential economic and health benefits. Confronted with the increasing large‐scale omics‐data set particularly the genome sequence ...released in tea plant, the construction of a comprehensive knowledgebase is urgently needed to facilitate the utilization of these data sets towards molecular breeding. We hereby present the first integrative and specially designed web‐accessible database, Tea Plant Information Archive (TPIA; http://tpia.teaplant.org). The current release of TPIA employs the comprehensively annotated tea plant genome as framework and incorporates with abundant well‐organized transcriptomes, gene expressions (across species, tissues and stresses), orthologs and characteristic metabolites determining tea quality. It also hosts massive transcription factors, polymorphic simple sequence repeats, single nucleotide polymorphisms, correlations, manually curated functional genes and globally collected germplasm information. A variety of versatile analytic tools (e.g. JBrowse, blast, enrichment analysis, etc.) are established helping users to perform further comparative, evolutionary and functional analysis. We show a case application of TPIA that provides novel and interesting insights into the phytochemical content variation of section Thea of genus Camellia under a well‐resolved phylogenetic framework. The constructed knowledgebase of tea plant will serve as a central gateway for global tea community to better understand the tea plant biology that largely benefits the whole tea industry.
Brick dark tea is a unique brick-formed tea compressed from the older, coarse and rough leaves and branches of
Camellia sinensis
var.
sinensis
and
C. sinensis
var.
assamica
mainly in Hunan, Sichuan ...and Yunnan provinces in China. Researches on brick dark tea have become increasingly popular owing to its special health benefits. A series of biochemical reactions occur during the special production—microbial fermentation stage and multitudinous components have been detected. Many of the functional components have been isolated and identified from brick dark tea. In this paper, modern manufacturing techniques about different kinds of brick dark tea and their effects on transformation of the chemical constituents, as well as the chemical components were reviewed and discussed.
Abstract
Tea is among the world’s most widely consumed non-alcoholic beverages and possesses enormous economic, health, and cultural values. It is produced from the cured leaves of tea plants, which ...are important evergreen crops globally cultivated in over 50 countries. Along with recent innovations and advances in biotechnologies, great progress in tea plant genomics and genetics has been achieved, which has facilitated our understanding of the molecular mechanisms of tea quality and the evolution of the tea plant genome. In this review, we briefly summarize the achievements of the past two decades, which primarily include diverse genome and transcriptome sequencing projects, gene discovery and regulation studies, investigation of the epigenetics and noncoding RNAs, origin and domestication, phylogenetics and germplasm utilization of tea plant as well as newly developed tools/platforms. We also present perspectives and possible challenges for future functional genomic studies that will contribute to the acceleration of breeding programs in tea plants.
Tea is one of the most popular non-alcoholic beverages worldwide. However, the tea plant, Camellia sinensis, is difficult to culture in vitro, to transform, and has a large genome, rendering little ...genomic information available. Recent advances in large-scale RNA sequencing (RNA-seq) provide a fast, cost-effective, and reliable approach to generate large expression datasets for functional genomic analysis, which is especially suitable for non-model species with un-sequenced genomes.
Using high-throughput Illumina RNA-seq, the transcriptome from poly (A)+ RNA of C. sinensis was analyzed at an unprecedented depth (2.59 gigabase pairs). Approximate 34.5 million reads were obtained, trimmed, and assembled into 127,094 unigenes, with an average length of 355 bp and an N50 of 506 bp, which consisted of 788 contig clusters and 126,306 singletons. This number of unigenes was 10-fold higher than existing C. sinensis sequences deposited in GenBank (as of August 2010). Sequence similarity analyses against six public databases (Uniprot, NR and COGs at NCBI, Pfam, InterPro and KEGG) found 55,088 unigenes that could be annotated with gene descriptions, conserved protein domains, or gene ontology terms. Some of the unigenes were assigned to putative metabolic pathways. Targeted searches using these annotations identified the majority of genes associated with several primary metabolic pathways and natural product pathways that are important to tea quality, such as flavonoid, theanine and caffeine biosynthesis pathways. Novel candidate genes of these secondary pathways were discovered. Comparisons with four previously prepared cDNA libraries revealed that this transcriptome dataset has both a high degree of consistency with previous EST data and an approximate 20 times increase in coverage. Thirteen unigenes related to theanine and flavonoid synthesis were validated. Their expression patterns in different organs of the tea plant were analyzed by RT-PCR and quantitative real time PCR (qRT-PCR).
An extensive transcriptome dataset has been obtained from the deep sequencing of tea plant. The coverage of the transcriptome is comprehensive enough to discover all known genes of several major metabolic pathways. This transcriptome dataset can serve as an important public information platform for gene expression, genomics, and functional genomic studies in C. sinensis.
Volatile terpenoids produced in tea plants (Camellia sinensis) are airborne signals interacting against other ecosystem members, but also pleasant odorants of tea products. Transcription regulation ...(including transcript processing) is pivotal for plant volatile terpenoid production. In this study, a terpene synthase gene CsLIS/NES was recovered from tea plants (C. sinensis cv. “Long‐Men Xiang”). CsLIS/NES transcription regulation resulted in 2 splicing forms: CsLIS/NES‐1 and CsLIS/NES‐2 lacking a 305 bp‐fragment at N‐terminus, both producing (E)‐nerolidol and linalool in vitro. Transgenic tobacco studies and a gene‐specific antisense oligo‐deoxynucleotide suppression applied in tea leaves indicated that CsLIS/NES‐1, localized in chloroplasts, acted as linalool synthase, whereas CsLIS/NES‐2 localized in cytosol, functioned as a potential nerolidol synthase, but not linalool synthase. Expression patterns of the 2 transcript isoforms in tea were distinctly different and responded differentially to the application of stress signal molecule methyl jasmonate. Leaf expression of CsLIS/NES‐1, but not CsLIS/NES‐2, was significantly induced by methyl jasmonate. Our data indicated that distinct transcript splicing regulation patterns, together with subcellular compartmentation of CsLIS/NE‐1 and CsLIS/NE‐2 implemented the linalool biosynthesis regulation in tea plants in responding to endogenous and exogenous regulatory factors.
Linalool and nerolidol produced in tea plants are not only airborne signals interacting against other ecosystem members for better plant fitness but also floral scent determinants of tea products. A better understanding of the mechanisms underlying their biosynthesis in tea plants may provide effective approaches for tea aroma quality and tea productivity improvement. In this study, tea CsLIS/NES gene was found being differentially involved in linalool and nerolidol biosynthesis due to its 2 splicing transcripts with distinct expression patterns. Regulation at transcription (including transcript processing) and subcellular compartmentation of the 2 CsLIS/NES transcripts implement the biosynthesis regulation of linalool and nerolidol in tea plants in responding to endogenous and exogenous regulatory factors.
Fu brick tea (FBT) is a unique post-fermented tea product which is fermented with fungi during the manufacturing process. In this study, we investigated the biochemical compositional changes ...occurring during the microbial fermentation process (MFP) of FBT based on non-targeted LC-MS, which was a comprehensive and unbiased methodology. Our data analysis took a two-phase approach: (1) comparison of FBT with other tea products using PCA analysis to exhibit the characteristic effect of MFP on the formation of Fu brick tea and (2) comparison of tea samples throughout the MFP of FBT to elucidate the possible key metabolic pathways produced by the fungi. Non-targeted LC-MS analysis clearly distinguished FBT with other tea samples and highlighted some interesting metabolic pathways during the MFP including B ring fission catechin. Our study demonstrated that those fungi had a significant influence on the biochemical profiles in the FBT and consequently contributed to its unique quality.
Neuronal apoptosis is the main pathological feature of spinal cord injury (SCI), while autophagy contributes to ameliorating neuronal damage via inhibition of apoptosis. Here, we investigated the ...role of tectonic family member 2 (TCTN2) long non‐coding RNA on apoptosis and autophagy in SCI. TCTN2 was down‐regulated in the spinal cord tissues of a rat model of SCI and in oxygen–glucose deprivation‐induced hypoxic SY‐SH‐5Y cells, while microRNA‐216b (miR‐216b) was up‐regulated. Overexpression of TCTN2 reduced neuron apoptosis by inducing autophagy, and TCTN2 was observed to negatively regulate miR‐216b. Furthermore, TCTN2 promoted autophagy to repress apoptosis through the miR‐216b–Beclin‐1 pathway, and overexpression of TCTN2 improved neurological function in the SCI rat model. In summary, our data suggest that TCTN2 enhances autophagy by targeting the miR‐216b–Beclin‐1 pathway, thereby ameliorating neuronal apoptosis and relieving spinal cord injury.
The role of lncRNA TCTN2 in apoptosis and autophagy in spinal cord injury (SCI) was explored. TCTN2 was observed to negatively regulate miR‐216b. TCTN2 reduced neuron apoptosis by inducing autophagy through the miR‐216b–Beclin‐1 pathway, and overexpression of TCTN2 improved neurological function in the SCI rat model. The study demonstrated that TCTN2 showed a neuroprotective role by ameliorating neuronal apoptosis in SCI.
•Jing-Wei Fu brick tea, a kind of brick dark tea, was chemically studied for the first time.•Four new B ring fission catechins (BRFCs) were isolated and identified from Jing-Wei Fu brick tea.•HPLC ...analysis showed that the level of major tea catechins dropped sharply in the final product.•Possible pathways for the degradation of major tea catechins and the generation of BRFCs were provided.
HPLC analysis of samples from four major fermentation procedures of Jing-Wei Fu brick tea showed that the level of major tea catechins epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) dropped increasingly to about 1/3 in the final product. Phytochemical study of the final product led to the discovery of four new B-ring fission metabolites of catechins (BRFCs) Fuzhuanin C–F (1–4) together with three known BRFCs (5–7), six known catechins (8–13), five simple phenols (14–18), seven flavones and flavone glycosides (19–25), two alkaloids (26, 27), three triterpenoids (28–30) and one steroid (31). The structures were elucidated by spectroscopic methods including 1D and 2D NMR, LC–HR-ESI-MS, IR, and CD spectra. Five compounds (16–18, 28, 29) were reported for the first time in tea. Possible pathways for the degradation of major tea catechins and the generation of BRFCs were also provided.
Tea is one of the most popular beverages across the world and is made exclusively from cultivars of Camellia sinensis. Many wild relatives of the genus Camellia that are closely related to C. ...sinensis are native to Southwest China. In this study, we first identified the distinct genetic divergence between C. sinensis and its wild relatives and provided a glimpse into the artificial selection of tea plants at a genome-wide level by analyzing 15,444 genomic SNPs that were identified from 18 cultivated and wild tea accessions using a high-throughput genome-wide restriction site-associated DNA sequencing (RAD-Seq) approach. Six distinct clusters were detected by phylogeny inferrence and principal component and genetic structural analyses, and these clusters corresponded to six Camellia species/varieties. Genetic divergence apparently indicated that C. taliensis var. bangwei is a semi-wild or transient landrace occupying a phylogenetic position between those wild and cultivated tea plants. Cultivated accessions exhibited greater heterozygosity than wild accessions, with the exception of C. taliensis var. bangwei. Thirteen genes with non-synonymous SNPs exhibited strong selective signals that were suggestive of putative artificial selective footprints for tea plants during domestication. The genome-wide SNPs provide a fundamental data resource for assessing genetic relationships, characterizing complex traits, comparing heterozygosity and analyzing putatitve artificial selection in tea plants.
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