Comparison of Metabolome and Transcriptome of Flavonoid Biosynthesis Pathway in a Purple-Leaf Tea Germplasm <i>Jinmingzao</i> and a Green-Leaf Tea Germplasm <i>Huangdan</i> reveals Their Relationship with Genetic Mechanisms of Color Formation

• Main Authors: Xuejin Chen, Pengjie Wang, Yucheng Zheng, Mengya Gu, Xinying Lin, Shuyan Wang, Shan Jin, Naixing Ye
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: International Journal of Molecular Sciences
• Subjects: <i>Camellia sinensis</i>; leaf coloration; flavonoid biosynthesis; widely targeted metabolomic; transcriptomic; coexpression analysis
• Online Access: https://www.mdpi.com/1422-0067/21/11/4167
• ISSN: 1661-6596; 1422-0067

Purple-leaf tea is a phenotype with unique color because of its high anthocyanin content. The special flavor of purple-leaf tea is highly different from that of green-leaf tea, and its main ingredient is also of economic value. To probe the genetic mechanism of the phenotypic characteristics of tea leaf color, we conducted widely targeted metabolic and transcriptomic profiling. The metabolites in the flavonoid biosynthetic pathway of purple- and green-leaf tea were compared, and results showed that phenolic compounds, including phenolic acids, flavonoids, and tannins, accumulated in purple-leaf tea. The high expression of genes related to flavonoid biosynthesis (e.g., <i>PAL</i> and <i>LAR</i>) exhibits the specific expression of biosynthesis and the accumulation of these metabolites. Our result also shows that two Cs<i>UFGT</i>s were positively related to the accumulation of anthocyanin. Moreover, genes encoding transcription factors that regulate flavonoids were identified by coexpression analysis. These results may help to identify the metabolic factors that influence leaf color differentiation and provide reference for future research on leaf color biology and the genetic improvement of tea.