title: A basic helix-loop-helix transcription factor DvIVS determines flower color intensity in cyanic dahlia cultivars.
abstract: The study was aimed to identify the factors that regulate the intensity of flower color in cyanic dahlia (Dahlia variabilis), using fifteen cultivars with different color intensities in their petals. The cultivars were classified into three groups based on their flavonoid composition: ivory white cultivars with flavones; purple and pink cultivars with flavones and anthocyanins; and red cultivars with flavones, anthocyanins, and chalcones. Among the purple, pink, and ivory white cultivars, an inverse relationship was detected between lightness, which was used as an indicator for color intensity and anthocyanin content. A positive correlation was detected between anthocyanin contents and the expression of some structural genes in the anthocyanin synthesis pathway that are regulated by DvIVS, a basic helix-loop-helix transcription factor. A positive correlation between anthocyanin content and expression of DvIVS was also found. The promoter region of DvIVS was classified into three types, with cultivars carrying Type 1 promoter exhibited deep coloring, those carrying Type 2 and/or Type 3 exhibited pale coloring, and those carrying Type 1 and Type 2 and/or Type 3 exhibited medium coloring. The transcripts of the genes from these promoters encoded full-length predicted proteins. These results suggested that the genotype of the promoter region in DvIVS is one of the key factors determining the flower color intensity.
authors.affiliation: Laboratory of Vegetable and Ornamental Horticulture, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan. sohno@kais.kyoto-u.ac.jp
authors.forename: Sho
authors.initials: S
authors.lastname: Ohno
authors.forename: Ayumi
authors.initials: A
authors.lastname: Deguchi
authors.forename: Munetaka
authors.initials: M
authors.lastname: Hosokawa
authors.forename: Fumi
authors.initials: F
authors.lastname: Tatsuzawa
authors.forename: Motoaki
authors.initials: M
authors.lastname: Doi
mesh_terms: D000872:Anthocyanins / Q000032:analysis / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D031944:Dahlia / Q000235:genetics* / Q000378:metabolism; D005419:Flavonoids / Q000378:metabolism*; D035264:Flowers / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D006863:Hydrogen-Ion Concentration; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics; D012313:RNA / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D051792:Basic Helix-Loop-Helix Proteins; D018076:DNA, Complementary; D005419:Flavonoids; D010940:Plant Proteins; D012313:RNA; D018749:RNA, Plant; D014157:Transcription Factors