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. 2021 Mar 1;8(1):42.
doi: 10.1038/s41438-021-00477-3.

Genome-wide association analysis identified molecular markers associated with important tea flavor-related metabolites

Kaixing Fang #  1 , Zhiqiang Xia #  2   3 , Hongjian Li  1 , Xiaohui Jiang  1 , Dandan Qin  1 , Qiushuang Wang  1 , Qing Wang  1 , Chendong Pan  1 , Bo Li  1 , Hualing Wu  4
Affiliations

Genome-wide association analysis identified molecular markers associated with important tea flavor-related metabolites

Kaixing Fang et al. Hortic Res. .

Abstract

The characteristic secondary metabolites in tea (theanine, caffeine, and catechins) are important factors contributing to unique tea flavors. However, there has been relatively little research on molecular markers related to these metabolites. Thus, we conducted a genome-wide association analysis of the levels of these tea flavor-related metabolites in three seasons. The theanine, caffeine, and catechin levels in Population 1 comprising 191 tea plant germplasms were examined, which revealed that their heritability exceeded 0.5 in the analyzed seasons, with the following rank order (highest to lowest heritabilities): (+)-catechin > (-)-gallocatechin gallate > caffeine = (-)-epicatechin > (-)-epigallocatechin-3-gallate > theanine > (-)-epigallocatechin > (-)-epicatechin-3-gallate > catechin gallate > (+)-gallocatechin. The SNPs detected by amplified-fragment SNP and methylation sequencing divided Population 1 into three groups and seven subgroups. An association analysis yielded 307 SNP markers related to theanine, caffeine, and catechins that were common to all three seasons. Some of the markers were pleiotropic. The functional annotation of 180 key genes at the SNP loci revealed that FLS, UGT, MYB, and WD40 domain-containing proteins, as well as ATP-binding cassette transporters, may be important for catechin synthesis. KEGG and GO analyses indicated that these genes are associated with metabolic pathways and secondary metabolite biosynthesis. Moreover, in Population 2 (98 tea plant germplasm resources), 30 candidate SNPs were verified, including 17 SNPs that were significantly or extremely significantly associated with specific metabolite levels. These results will provide a foundation for future research on important flavor-related metabolites and may help accelerate the breeding of new tea varieties.

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Conflict of interest statement

The authors declare that they have no conflict of interest.

Figures

Fig. 1
Fig. 1. Levels of 10 metabolites in 191 germplasms in three seasons.
a Box charts of 10 metabolites in 191 germplasms in three seasons. The seasons are presented on the abscissa, whereas the metabolite dry matter levels are presented on the ordinate. a1, C; a2, CAF; a3, CG; a4, EC; a5, ECG; a6, EGC; a7 EGCG; a8, GC; a9, GCG; a10, TN. b Heat map presenting the correlations among metabolite levels in different seasons. The depth of the scale color represents the strength of the correlation
Fig. 2
Fig. 2. Population structures and relationships.
a Analysis of the group structures of 191 tea resources. b Principal component analysis of 191 tea resources. c Phylogenetic tree consisting of 191 tea resources
Fig. 3
Fig. 3. Genome-wide association analysis of C in different seasons.
a1–a3 Manhattan charts of the C correlation analysis in the spring, summer, and autumn. b1–b3 QQ diagrams of the C correlation analysis in the spring, summer, and autumn
Fig. 4
Fig. 4. SNPs and genes identified by genome-wide association analysis.
a Detection of catechin-related molecular markers in three seasons. b Top 20 enriched KEGG pathways among the genes identified by genome-wide association analysis
Fig. 5
Fig. 5. Localization and verification of candidate SNPs.
a SNP loci in some genes identified by an association analysis. b F values and correlation coefficients of verified SNPs. c Polymorphism of validated SNPs in the analyzed resources
See this image and copyright information in PMC

References

    1. Yamanishi T. Flavor of tea. Food Rev. Int. 1995;11:371–546. doi: 10.1080/87559129509541049. - DOI
    1. Chen GH, Yang CY, Lee SJ, Wu CC, Tzen JTC. Catechin content and the degree of its galloylation in oolong tea are inversely correlated with cultivation altitude. J. Food Drug Anal. 2014;22:303–309. doi: 10.1016/j.jfda.2013.12.001. - DOI - PMC - PubMed
    1. Han Z, et al. Data on green tea flavor determinantes as affected by cultivars and manufacturing processes. Data Brief. 2017;10:492–498. doi: 10.1016/j.dib.2016.12.025. - DOI - PMC - PubMed
    1. Zhang W, et al. The effects and mechanisms of epigallocatechin-3-gallate on reversing multidrug resistance in cancer. Trends Food Sci. Tech. 2019;93:221–233. doi: 10.1016/j.tifs.2019.09.017. - DOI
    1. Liang Y, Shi M. Advances in tea plant genetics and breeding. J. Tea Sci. 2015;35:103–109.