title: Disruption of a CAROTENOID CLEAVAGE DIOXYGENASE 4 gene converts flower colour from white to yellow in Brassica species.
abstract: In Brassica napus, yellow petals had a much higher content of carotenoids than white petals present in a small number of lines, with violaxanthin identified as the major carotenoid compound in yellow petals of rapeseed lines. Using positional cloning we identified a carotenoid cleavage dioxygenase 4 gene, BnaC3.CCD4, responsible for the formation of flower colour, with preferential expression in petals of white-flowered B. napus lines. Insertion of a CACTA-like transposable element 1 (TE1) into the coding region of BnaC3.CCD4 had disrupted its expression in yellow-flowered rapeseed lines. α-Ionone was identified as the major volatile apocarotenoid released from white petals but not from yellow petals. We speculate that BnaC3.CCD4 may use δ- and/or α-carotene as substrates. Four variations, including two CACTA-like TEs (alleles M1 and M4) and two insertion/deletions (INDELs, alleles M2 and M3), were identified in yellow-flowered Brassica oleracea lines. The two CACTA-like TEs were also identified in the coding region of BcaC3.CCD4 in Brassica carinata. However, the two INDELs were not detected in B. napus and B. carinata. We demonstrate that the insertions of TEs in BolC3.CCD4 predated the formation of the two allotetraploids.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Bao
authors.initials: B
authors.lastname: Zhang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Yao
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Jiangsheng
authors.initials: J
authors.lastname: Wu
authors.affiliation: Southern Cross Plant Science, Southern Cross University, Lismore, NSW, 2480, Australia.
authors.forename: Graham J
authors.initials: GJ
authors.lastname: King
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Kede
authors.initials: K
authors.lastname: Liu
mesh_terms: D055162:Biocatalysis; D005075:Biological Evolution; D001937:Brassica / Q000201:enzymology* / Q000235:genetics*; D002338:Carotenoids / Q000378:metabolism; D003001:Cloning, Molecular; D004251:DNA Transposable Elements / Q000235:genetics; D049308:Dioxygenases / Q000235:genetics* / Q000378:metabolism; D035264:Flowers / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D014644:Genetic Variation; D008954:Models, Biological; D008969:Molecular Sequence Data; D010802:Phylogeny; D010858:Pigmentation / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013347:Subcellular Fractions / Q000378:metabolism; D013379:Substrate Specificity; D055549:Volatile Organic Compounds / Q000032:analysis
chemical_list: D004251:DNA Transposable Elements; D010940:Plant Proteins; D055549:Volatile Organic Compounds; D002338:Carotenoids; D049308:Dioxygenases
keywords: Brassica; apocarotenoid; carotenoid; carotenoid cleavage dioxygenase 4; evolutional mechanism; flower colour