Identification and distribution of a single nucleotide polymorphism responsible for the catechin content in tea plants

Abstract

Catechins are the predominant products in tea plants and have essential functions for both plants and humans. Several genes encoding the enzymes regulating catechin biosynthesis have been identified, and the identification of single nucleotide polymorphisms (SNPs) resulting in nonsynonymous mutations within these genes can be used to establish a functional link to catechin content. Therefore, the transcriptomes of two parents and four filial offspring were sequenced using next-generation sequencing technology and aligned to the reference genome to enable SNP mining. Subsequently, 176 tea plant accessions were genotyped based on candidate SNPs using kompetitive allelespecific polymerase chain reaction (KASP). The catechin contents of these samples were characterized by highperformance liquid chromatography (HPLC), and analysis of variance (ANOVA) was subsequently performed to determine the relationship between genotypes and catechin content. As a result of these efforts, a SNP within the chalcone synthase (CHS) gene was shown to be functionally associated with catechin content. Furthermore, the geographical and interspecific distribution of this SNP was investigated. Collectively, these results will contribute to the early evaluation of tea plants and serve as a rapid tool for accelerating targeted efforts in tea breeding.

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

“…Zhang et al combined RNA sequencing results for 176 resources and data regarding the levels of catechin components in a correlation analysis, which revealed that CsANR, CsF3′5′H, and CsMYB5 may influence catechin levels 12 . These studies involving natural populations examined the linkage disequilibrium between marker genes to correlate phenotypic traits with genotypes and detect marker gene loci closely related to the phenotype of interest 13 , 14 . Unlike QTL mapping, this method does not require the construction of a genetic map, there are no significant differences in the parental genotypes when QTLs are mapped, and multiple allelic variations in the same locus can be detected simultaneously.…”

An ancient whole-genome duplication event and its contribution to flavor compounds in the tea plant (Camellia sinensis)

“…The molecular mechanisms underlying tea flavor have been widely explored 11 , 12 . The metabolic pathways and accumulation mechanisms of catechins, caffeine, and theanine, the main secondary metabolites in tea, have been studied thoroughly 11 .…”

From the Wild to the Cup: Tracking Footprints of the Tea Species in Time and Space

“…Following its domestication, the tea plant underwent intensive cycles of further breeding and selection in order to improve its capacity to withstand biotic and abiotic stresses, as well as to enhance its organoleptic attributes such as aroma, taste, color, and texture (32,54). For instance, recent transcriptomic and genomic analyses suggest that metabolic pathways in tea plants (particularly flavonoid biosynthetic pathways) underwent strong selection during the domestication process (50,55,56). Similarly, flavor and stress (biotic and abiotic) tolerance are among the main traits that were selected for during tea domestication or improvement processes (57).…”

“…We argue that as CSA spread northwards within China, and later to Korea and Japan, cold tolerance became a necessary trait for survival, thus persistent selection for this attribute eventually produced CSS. This idea is reinforced by the fact that CSA has a relatively higher catechin content (56,59), a phenotype that was recently associated with a primitive genotype predominantly found at the center of tea origin in Yunnan (55). Further insights on the precise genetic mechanism underlying tea domestication can be obtained using genome-wide association studies (GWAS) on a world-wide collection of tea accessions alongside Camellia wild species, as recently applied in clarifying the domestication history of castor bean (60).…”