title: Characterization of two tartary buckwheat R2R3-MYB transcription factors and their regulation of proanthocyanidin biosynthesis.
abstract: Tartary buckwheat (Fagopyrum tataricum Gaertn.) contains high concentrations of flavonoids. The flavonoids are mainly represented by rutin, anthocyanins and proanthocyanins in tartary buckwheat. R2R3-type MYB transcription factors (TFs) play key roles in the transcriptional regulation of the flavonoid biosynthetic pathway. In this study, two TF genes, FtMYB1 and FtMYB2, were isolated from F. tataricum and characterized. The results of bioinformatic analysis indicated that the putative FtMYB1 and FtMYB2 proteins belonged to the R2R3-MYB family and displayed a high degree of similarity with TaMYB14 and AtMYB123/TT2. In vitro and in vivo evidence both showed the two proteins were located in the nucleus and exhibited transcriptional activation activities. During florescence, both FtMYB1 and FtMYB2 were more highly expressed in the flowers than any other organ. The overexpression of FtMYB1 and FtMYB2 significantly enhanced the accumulation of proanthocyanidins (PAs) and showed a strong effect on the target genes' expression in Nicotiana tabacum. The expression of dihydroflavonol-4-reductase (DFR) was upregulated to 5.6-fold higher than that of control, and the expression level was lower for flavonol synthase (FLS). To our knowledge, this is the first functional characterization of two MYB TFs from F. tataricum that control the PA pathway.
authors.affiliation: College of Life and Basic Sciences, Sichuan Agricultural University, Ya'an, 625014, China.
authors.forename: Yue-Chen
authors.initials: YC
authors.lastname: Bai
authors.forename: Cheng-Lei
authors.initials: CL
authors.lastname: Li
authors.forename: Jin-Wen
authors.initials: JW
authors.lastname: Zhang
authors.forename: Shuang-Jiang
authors.initials: SJ
authors.lastname: Li
authors.forename: Xiao-Peng
authors.initials: XP
authors.lastname: Luo
authors.forename: Hui-Peng
authors.initials: HP
authors.lastname: Yao
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Hai-Xia
authors.initials: HX
authors.lastname: Zhao
authors.forename: Sang-Un
authors.initials: SU
authors.lastname: Park
authors.forename: Qi
authors.initials: Q
authors.lastname: Wu
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics; D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics; D001483:Base Sequence; D019295:Computational Biology; D019612:Fagopyrum / Q000235:genetics* / Q000378:metabolism; D005419:Flavonoids / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D044945:Proanthocyanidins / Q000378:metabolism*; D016415:Sequence Alignment; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: D000872:Anthocyanins; D029681:Arabidopsis Proteins; C482738:BOTRYTIS SUSCEPTIBLE1 protein, Arabidopsis; D005419:Flavonoids; D010940:Plant Proteins; D044945:Proanthocyanidins; D014157:Transcription Factors; D010088:Oxidoreductases; D000429:Alcohol Oxidoreductases; C056570:dihydroflavanol 4-reductase; C085313:flavonol synthase