title: Transcriptome Analysis Reveals Key Flavonoid 3'-Hydroxylase and Flavonoid 3',5'-Hydroxylase Genes in Affecting the Ratio of Dihydroxylated to Trihydroxylated Catechins in Camellia sinensis.
abstract: The ratio of dihydroxylated to trihydroxylated catechins (RDTC) is an important indicator of tea quality and biochemical marker for the study of genetic diversity. It is reported to be under genetic control but the underlying mechanism is not well understood. Flavonoid 3'-hydroxylase (F3'H) and flavonoid 3',5'-hydroxylase (F3'5'H) are key enzymes involved in the formation of dihydroxylated and trihydroxylated catechins. The transcriptome and HPLC analysis of tea samples from Longjing43 and Zhonghuang2 under control and shading treatment were performed to assess the F3'H and F3'5'H genes that might affect RDTC. A total of 74.7 million reads of mRNA seq (2×101bp) data were generated. After de novo assembly, 109,909 unigenes were obtained, and 39,982 of them were annotated using 7 public databases. Four key F3'H and F3'5'H genes (including CsF3'5'H1, CsF3'H1, CsF3'H2 and CsF3'H3) were identified to be closely correlated with RDTC. Shading treatment had little effect on RDTC, which was attributed to the stable expression of these key F3'H and F3'5'H genes. The correlation of the coexpression of four key genes and RDTC was further confirmed among 13 tea varieties by real time PCR and HPLC analysis. The coexpression of three F3'H genes and a F3'5'H gene may play a key role in affecting RDTC in Camellia sinensis. The current results may establish valuable foundation for further research about the mechanism controlling catechin composition in tea.
authors.affiliation: National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, Zhejiang 310008, China; Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Kang
authors.initials: K
authors.lastname: Wei
authors.affiliation: National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, Zhejiang 310008, China; Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Wang
authors.affiliation: National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, Zhejiang 310008, China; Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Chengcai
authors.initials: C
authors.lastname: Zhang
authors.affiliation: National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, Zhejiang 310008, China; Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Liyun
authors.initials: L
authors.lastname: Wu
authors.affiliation: National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, Zhejiang 310008, China; Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Hailin
authors.initials: H
authors.lastname: Li
authors.affiliation: National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, Zhejiang 310008, China; Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Zhang
authors.affiliation: National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), 9 Meiling South Road, Hangzhou, Zhejiang 310008, China; Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Cheng
mesh_terms: D028241:Camellia sinensis / Q000201:enzymology / Q000235:genetics; D002392:Catechin / Q000096:biosynthesis / Q000235:genetics; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D017343:Genes, Plant / Q000502:physiology*; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics; D013045:Species Specificity; D059467:Transcriptome / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D002392:Catechin; D003577:Cytochrome P-450 Enzyme System; C084258:flavonoid 3',5'-hydroxylase; C038888:flavonoid 3'-hydroxylase