title: Comparative transcriptomic analysis of key genes involved in flavonoid biosynthetic pathway and identification of a flavonol synthase from Artemisia annua L.
abstract: The regulatory mechanism of flavonoids, which synergise anti-malarial and anti-cancer compounds in Artemisia annua, is still unclear. In this study, an anthocyanidin-accumulating mutant callus was induced from A. annua and comparative transcriptomic analysis of wild-type and mutant calli performed, based on the next-generation Illumina/Solexa sequencing platform and de novo assembly. A total of 82,393 unigenes were obtained and 34,764 unigenes were annotated in the public database. Among these, 87 unigenes were assigned to 14 structural genes involved in the flavonoid biosynthetic pathway and 37 unigenes were assigned to 17 structural genes related to metabolism of flavonoids. More than 30 unigenes were assigned to regulatory genes, including R2R3-MYB, bHLH and WD40, which might regulate flavonoid biosynthesis. A further 29 unigenes encoding flavonoid biosynthetic enzymes or transcription factors were up-regulated in the mutant, while 19 unigenes were down-regulated, compared with the wild type. Expression levels of nine genes involved in the flavonoid pathway were compared using semi-quantitative RT-PCR, and results were consistent with comparative transcriptomic analysis. Finally, a putative flavonol synthase gene (AaFLS1) was identified from enzyme assay in vitro and in vivo through heterogeneous expression, and confirmed comparative transcriptomic analysis of wild-type and mutant callus. The present work has provided important target genes for the regulation of flavonoid biosynthesis in A. annua.
authors.affiliation: Hunan Collaborative Innovation for Utilization of Botanical Functional Ingredients, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture and Hardening, Hunan Agricultural University, Changsha, China.|Department of Tea Science, College of Horticulture and Hardening, Hunan Agricultural University, Changsha, China.
authors.forename: S
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Tea Science, College of Horticulture and Hardening, Hunan Agricultural University, Changsha, China.
authors.forename: L
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Tea Science, College of Horticulture and Hardening, Hunan Agricultural University, Changsha, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Tea Science, College of Horticulture and Hardening, Hunan Agricultural University, Changsha, China.
authors.forename: S
authors.initials: S
authors.lastname: Xiong
authors.affiliation: Hunan Collaborative Innovation for Utilization of Botanical Functional Ingredients, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture and Hardening, Hunan Agricultural University, Changsha, China.
authors.forename: J
authors.initials: J
authors.lastname: Long
authors.affiliation: Hunan Collaborative Innovation for Utilization of Botanical Functional Ingredients, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture and Hardening, Hunan Agricultural University, Changsha, China.|Department of Tea Science, College of Horticulture and Hardening, Hunan Agricultural University, Changsha, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Tea Science, College of Horticulture and Hardening, Hunan Agricultural University, Changsha, China.
authors.forename: N
authors.identifier: http://orcid.org/0000-0003-2526-8911
authors.initials: N
authors.lastname: Tian
mesh_terms: D031172:Artemisia annua / Q000235:genetics / Q000378:metabolism*; D005419:Flavonoids / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome / Q000235:genetics
chemical_list: D005419:Flavonoids; D010940:Plant Proteins; D010088:Oxidoreductases; C085313:flavonol synthase
keywords: Anthocyanin; comparative transcriptome; flavonoids