Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2006
Publication Date: 12/22/2006
Citation: Just, B.J., Santos, C., Boiteux, L.S., Oloizia, B.B., Simon, P.W. 2006. Carotenoid biosynthesis structural genes in carrot (Daucus carota): isolation, sequence-characterization, single nucleotide polymorphism (SNP) markers and genome mapping. Journal of Theoretical and Applied Genetics. 114:693-704. Interpretive Summary: The orange carotenoid pigments in carrots are a very important source of vitamin A in the US diet. While the enzymes in the biochemical pathway that results in the formulation of carotenoids have been studied in several plants, the genes that control these enzymes have not been studied in carrots. In this research, we identified the genes that code the carotenoid biosynthetic enzymes in carrot, determines the DNA sequence of those genes and located those genes on carrot chromosomes. This information is the first study determining any of this information for carrots. It is important and useful for fundamental plant scientists in enlarging the genetic database and it is important for carrot breeders and geneticists in providing information useful in breeding carrots with high carotenoid control to sustain and improve the healthiness of the food supply for US consumers.
Technical Abstract: Carotenoid pigments are important components in plants and in the human diet. Carrots (Daucus carota var. sativus L.) are an excellent dietary source of '- and '-carotene. While the biosynthesis of carotenoid pigments has been studied in detail in several species, very little comparable information exists for carrot. In this study we utilized published carrot sequence and homologous sequence from other species to develop primers for 24 putative carotenoid biosynthesis enzymes in carrot. Twenty-two of these genes were placed on the carrot genetic linkage map developed from a population of B493 (orange-rooted inbred) x Queen Anne’s lace (white-rooted wild carrot). These mapped genes can serve as candidate genes for some of the known carotenoid variants in carrot and can serve as anchor loci on future carrot linkage maps since they mapped to eight of the nine linkage groups in carrot. Using primers for each gene with cDNA pools from B493, RACE PCR and reverse transcriptase PCR were used to amplify and sequence the full-length transcript for twenty expressed carotenoid biosynthesis genes and sequences were submitted to GenBank.