Insight into Catechins Metabolic Pathways of Camellia sinensis Based on Genome and Transcriptome Analysis

Abstract

Tea is an important economic crop with a 3.02 Gb genome. It accumulates various bioactive compounds, especially catechins, which are closely associated with tea flavor and quality. Catechins are biosynthesized through the phenylpropanoid and flavonoid pathways, with 12 structural genes being involved in their synthesis. However, we found that in Camellia sinensis the understanding of the basic profile of catechins biosynthesis is still unclear. The gene structure, locus, transcript number, transcriptional variation, and function of multigene families have not yet been clarified. Our previous studies demonstrated that the accumulation of flavonoids in tea is species, tissue, and induction specific, which indicates that gene coexpression patterns may be involved in tea catechins and flavonoids biosynthesis. In this paper, we screened candidate genes of multigene families involved in the phenylpropanoid and flavonoid pathways based on an analysis of genome and transcriptome sequence data. The authenticity of candidate genes was verified by PCR cloning, and their function was validated by reverse genetic methods. In the present study, 36 genes from 12 gene families were identified and were accessed in the NCBI database. During this process, some intron retention events of the CsCHI and CsDFR genes were found. Furthermore, the transcriptome sequencing of various tea tissues and subcellular location assays revealed coexpression and colocalization patterns. The correlation analysis showed that CsCHIc, CsF3'H, and CsANRb expression levels are associated significantly with the concentration of soluble PA as well as the expression levels of CsPALc and CsPALf with the concentration of insoluble PA. This work provides insights into catechins metabolism in tea and provides a foundation for future studies.

Fulvic acid ameliorates drought stress-induced damage in tea plants by regulating the ascorbate metabolism and flavonoids biosynthesis

“…The qRT-PCR analyses were conducted with mRNA from the tea shoots. The method followed the procedures described in a previous report [56]. The triplicates of each reaction were performed, and GAPDH sequence was used as endogenous control.…”

Insights into Tissue-specific Specialized Metabolism in Tieguanyin Tea Cultivar by Untargeted Metabolomics

“…Great efforts have been made by the tea research community to functionally characterize the bioactive components in tea. In particular, catechins, caffeine, and theanine, three of the most characteristic metabolites known to be closely associated with tea flavor and quality, have been extensively studied molecularly and biochemically [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. With the recent release of genome sequences for C. sinensis var.…”

Unraveling the Roles of Regulatory Genes during Domestication of Cultivated Camellia: Evidence and Insights from Comparative and Evolutionary Genomics

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“…Through the transcriptomics analysis of leaf tissues from four tea plant cultivars ( C. sinensis ), 146,342 pairs of putative orthologs were generated and 217 common DEGs were found [ 29 ]. A similar work characterized the four tissue types of C. sinensis in which 36 catechins and flavonoids biosynthesis were identified [ 28 ]. These studies indicated that the biosynthesis pathways of secondary metabolites in different Camellia species were largely conserved and the changes of regulatory genes might play a key role in the diversity of chemical compositions.…”