title: Functional natural allelic variants of flavonoid 3',5'-hydroxylase gene governing catechin traits in tea plant and its relatives.
abstract: Functional allelic variants of the flavonoid 3',5'-hydroxylase (F3'5'H) gene provides new information of F3'5'H function of tea plant and its relatives. This insight may serve as the foundation upon which to advance molecular breeding in the tea plant. Catechins are the active components of tea that determine its quality and health attributes. This study established the first integrated genomic strategy for deciphering the genetic basis of catechin traits of tea plant. With the RNA-sequencing analysis of bulked segregants representing the tails of a F1 population segregated for total catechin content, we identified a flavonoid 3',5'-hydroxylase (F3'5'H) gene. F3'5'H had one copy in the genomic DNA of tea plant. Among 202 tea accessions, we identified 120 single nucleotide polymorphisms (SNPs) at F3'5'H locus. Seventeen significant marker-trait associations were identified by association mapping in multiple environments, which were involved in 10 SNP markers, and the traits including the ratio of di/tri-hydroxylated catechins and catechin contents. The associated individual and combination of SNPs explained 4.5-25.2 and 53.0-63.0% phenotypic variations, respectively. In the F1 population (validation population), the catechin trait variation percentages explained by F3'5'H diplotype were 6.9-74.3%. The genotype effects of ten functional SNPs in the F1 population were all consistent with the association population. Furthermore, the function of SNP-711/-655 within F3'5'H was validated by gene expression analysis. Altogether, our work indicated functional SNP allelic variants within F3'5'H governing the ratio of di/tri-hydroxylated catechins and catechin contents. The strong catechin-associated SNPs identified in this study can be used for future marker-assisted selection to improve tea quality.
authors.affiliation: Tea Research Institute of the Chinese Academy of Agricultural Sciences, National Center for Tea Improvement, Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China.
authors.forename: Ji-Qiang
authors.initials: JQ
authors.lastname: Jin
authors.affiliation: Tea Research Institute of the Chinese Academy of Agricultural Sciences, National Center for Tea Improvement, Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China.
authors.forename: Jian-Qiang
authors.initials: JQ
authors.lastname: Ma
authors.affiliation: Tea Research Institute of the Chinese Academy of Agricultural Sciences, National Center for Tea Improvement, Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China.
authors.forename: Ming-Zhe
authors.initials: MZ
authors.lastname: Yao
authors.affiliation: Tea Research Institute of the Chinese Academy of Agricultural Sciences, National Center for Tea Improvement, Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China.
authors.forename: Chun-Lei
authors.initials: CL
authors.lastname: Ma
authors.affiliation: Tea Research Institute of the Chinese Academy of Agricultural Sciences, National Center for Tea Improvement, Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China. liangchen@tricaas.com.
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
mesh_terms: D000483:Alleles; D053898:Biosynthetic Pathways / Q000235:genetics; D028241:Camellia sinensis / Q000201:enzymology* / Q000235:genetics*; D002392:Catechin / Q000378:metabolism*; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D005419:Flavonoids / Q000096:biosynthesis / Q000737:chemistry; D018628:Gene Dosage; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D056726:Genetic Association Studies; D014644:Genetic Variation; D005838:Genotype; D015810:Linkage Disequilibrium / Q000235:genetics; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D019655:Quantitative Trait, Heritable; D015203:Reproducibility of Results
chemical_list: D005419:Flavonoids; D002392:Catechin; D003577:Cytochrome P-450 Enzyme System; C084258:flavonoid 3',5'-hydroxylase
keywords: Allelic variants; Association mapping; Bulked segregant RNA-Seq; Catechin; Flavonoid 3′,5′-Hydroxylase; Tea plant