Restriction site-associated DNA sequencing (RAD-seq) of tea plant (Camellia sinensis) in Sichuan province, China, provides insights into free amino acid and polyphenol contents of tea

• Published in: PloS one Vol. 19; no. 12; p. e0314144
• Main Authors: Wang, Xiaoping, Sun, Minshan, Xiong, Yuanyuan, Liu, Xiao, Li, Chunhua, Wang, Yun, Tang, Xiaobo
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 05.12.2024; Public Library of Science (PLoS)
• Subjects: Amino acid composition; Amino acids; Amino Acids - analysis; Amino Acids - metabolism; Biology and Life Sciences; Breeding methods; Camellia sinensis - genetics; Camellia sinensis - metabolism; Cellular stress response; Chemical interactions; China; Climatic conditions; Cluster analysis; Composition; Computer and Information Sciences; Cultivars; DNA sequencing; Evolution; Evolution & development; Frequency distribution; Gene sequencing; Genes; Genetic analysis; Genetic divergence; Genetic diversity; Genetic testing; Genomes; Medicine and Health Sciences; Normal distribution; Phenolic compounds; Phenols; Phylogenetics; Phylogeny; Physical Sciences; Plant breeding; Polymorphism, Single Nucleotide; Polyphenols; Polyphenols - analysis; Polyphenols - metabolism; Population genetics; Population structure; Sensory properties; Sequence Analysis, DNA; Single-nucleotide polymorphism; Software; Structural analysis; Tea; Tea - chemistry; Tea - genetics; China; Yangtze River
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0314144

Worldwide, tea is a popular beverage; within the realm of Chinese tea, Sichuan tea holds particular significance for its role in the origin and composition of Chinese tea cultivars. Sichuan tea is noted for its rich content of free amino acids (FAAs) and tea polyphenols (TPs), which has made it an important subject for studying genetic diversity and the genes regulating these compounds. In this study, 139 varieties of tea were collected from areas in Sichuan Province, China, with similar geographical and climatic conditions. The FAA content was approximately 3% and the TP content was approximately 17%. Using RAD sequencing, 5,656,224 variant loci were identified, primarily comprising SNPs (94.17%) and indels (5.83%). Evolutionary analysis revealed that genetic divergence was not closely linked to the collection location. Population structure analysis confirmed a division into two main populations having a similar composition to the phylogenetic clusters. Screening for FAA-related SNPs identified significant loci associated with 33 genes that potentially regulate FAA content. Similarly, TP-related analysis pinpointed 8 SNPs significantly linked to 20 candidate genes. Notably, genetic associations hinted at the genes involved in the stress response and the accumulation of phenolic compounds, enhancing the understanding of determinants of tea quality. This research underscores the potential for molecular breeding based on genetic insights, suggesting pathways to improve the FAA and TP contents in tea. These findings not only provide a solid foundation for exploring gene–chemical interactions but also offer practical strategies for improving the nutritional and sensory attributes of tea cultivars through informed breeding practices.