The Tea Tree Genome Provides Insights into Tea Flavor and Independent Evolution of Caffeine Biosynthesis

Autor: Jun-Ying Jiao, Haibin Zhang, Hui Huang, Shu-Yan Mao, Kui Li, De-Jiang Ni, Yuan Liu, Wei Li, Hong Nan, Yuan Zhao, Dan Zhang, Chao Shi, Ben-Ying Liu, Jun Sheng, Jian-Jun Jiang, Cong Shi, Evan E. Eichler, Yan Tong, En-Hua Xia, Li-Zhi Gao, Yue Yu, Yun-Long Liu, Yun Zhang, Li-Ping Zhang, Changhoon Kim, Ting Zhu, Sheng-Fu Shao, You-Jie Zhao, Qun-Jie Zhang
Rok vydání: 2017
Předmět:
Zdroj: Molecular Plant. 10:866-877
ISSN: 1674-2052
DOI: 10.1016/j.molp.2017.04.002
Popis: Tea is the world's oldest and most popular caffeine-containing beverage with immense economic, medicinal, and cultural importance. Here, we present the first high-quality nucleotide sequence of the repeat-rich (80.9%), 3.02-Gb genome of the cultivated tea tree Camellia sinensis. We show that an extraordinarily large genome size of tea tree is resulted from the slow, steady, and long-term amplification of a few LTR retrotransposon families. In addition to a recent whole-genome duplication event, lineage-specific expansions of genes associated with flavonoid metabolic biosynthesis were discovered, which enhance catechin production, terpene enzyme activation, and stress tolerance, important features for tea flavor and adaptation. We demonstrate an independent and rapid evolution of the tea caffeine synthesis pathway relative to cacao and coffee. A comparative study among 25 Camellia species revealed that higher expression levels of most flavonoid- and caffeine- but not theanine-related genes contribute to the increased production of catechins and caffeine and thus enhance tea-processing suitability and tea quality. These novel findings pave the way for further metabolomic and functional genomic refinement of characteristic biosynthesis pathways and will help develop a more diversified set of tea flavors that would eventually satisfy and attract more tea drinkers worldwide.
Databáze: OpenAIRE
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