title: A novel gene IBF1 is required for the inhibition of brown pigment deposition in rice hull furrows.
abstract: The role of flavonoids as the major red, blue, purple and brown pigments in plants has gained these secondary products a great deal of attention over the years. In this study, we characterized a rice inhibitor for brown furrows1 (ibf1) mutant. In the ibf1 mutant, brown pigments specifically accumulate in hull furrows during seed maturation and reach a maximum level in dry seeds. Higher amounts of total flavonoids and anthocyanin in hull may be responsible for the brown pigmentation of ibf1. The IBF1 gene, which encodes a similar kelch repeat-containing F-box protein, was isolated by map-based cloning approach. Real-time RT-PCR and GUS activity assays revealed that IBF1 specifically expressed in reproductive tissues. GFP-IBF1 fusion protein mainly localized in cytoplasm. The expression of some major structural enzymatic genes involved in flavonoids biosynthesis could be up- or down-regulated to some different extent in ibf1 mutant. Our data suggested that IBF1 as a suppressor could inhibit the brown pigmentation of rice hull furrows.
authors.affiliation: State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Shao
authors.forename: Qian
authors.initials: Q
authors.lastname: Qian
authors.forename: Ding
authors.initials: D
authors.lastname: Tang
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Zhukuan
authors.initials: Z
authors.lastname: Cheng
authors.forename: Qiong
authors.initials: Q
authors.lastname: Luo
mesh_terms: D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000096:biosynthesis; D053898:Biosynthetic Pathways / Q000235:genetics; D035264:Flowers / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D005816:Genetic Complementation Test; D005966:Glucuronidase / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D012275:Oryza / Q000235:genetics*; D010641:Phenotype; D010802:Phylogeny; D010858:Pigmentation / Q000235:genetics*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D021381:Protein Transport; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D010940:Plant Proteins; D005966:Glucuronidase