title: Retrotransposons control fruit-specific, cold-dependent accumulation of anthocyanins in blood oranges.
abstract: Traditionally, Sicilian blood oranges (Citrus sinensis) have been associated with cardiovascular health, and consumption has been shown to prevent obesity in mice fed a high-fat diet. Despite increasing consumer interest in these health-promoting attributes, production of blood oranges remains unreliable due largely to a dependency on cold for full color formation. We show that Sicilian blood orange arose by insertion of a Copia-like retrotransposon adjacent to a gene encoding Ruby, a MYB transcriptional activator of anthocyanin production. The retrotransposon controls Ruby expression, and cold dependency reflects the induction of the retroelement by stress. A blood orange of Chinese origin results from an independent insertion of a similar retrotransposon, and color formation in its fruit is also cold dependent. Our results suggest that transposition and recombination of retroelements are likely important sources of variation in Citrus.
authors.affiliation: John Ines Centre, Norwich NR4 7UH, United Kingdom.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Butelli
authors.forename: Concetta
authors.initials: C
authors.lastname: Licciardello
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jianjun
authors.initials: J
authors.lastname: Liu
authors.forename: Steve
authors.initials: S
authors.lastname: Mackay
authors.forename: Paul
authors.initials: P
authors.lastname: Bailey
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Reforgiato-Recupero
authors.forename: Cathie
authors.initials: C
authors.lastname: Martin
mesh_terms: D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000096:biosynthesis*; D032084:Citrus sinensis / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D003080:Cold Temperature; D018744:DNA, Plant / Q000235:genetics; D005638:Fruit / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018626:Retroelements; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D018744:DNA, Plant; D010940:Plant Proteins; D018626:Retroelements; D014157:Transcription Factors