Submitted to: Carotenoid Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 8/19/1999
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: Plant carotenoids play an important role in human nutrition and health, and thus it would be desirable to have the capacity to selectively enhance carotenoid content and composition in crops. To gain insight into the control of carotenoid biosynthesis, we are characterizing a novel spontaneous mutant of cauliflower (Brassica oleracea L. var. botrytis) that texhibits a distinctive orange coloration in the meristematic region, the curd, the pith, and the vasculature at the base of the petioles. The mutant phenotype is semi-dominant and is encoded by a single gene, which has been designated Or. HPLC analysis of carotenoid composition and content in the mutant revealed that beta-carotene is the predominant carotenoid that accumulates in the orange tissues. Further, the levels of beta-carotene in these tissues can be several hundred fold higher than those found in wildtype cauliflower. Results from northern analyses indicated that several ldifferent carotenoid biosynthetic genes are expressed at a somewhat higher level in the orange tissues of the mutant relative to those levels observed in comparable tissues of wildtype cauliflower. However, it is unclear if this alone is responsible for the beta-carotene accumulation. Research efforts are focusing on the isolation of the Or gene by employing a range of molecular strategies. It is our hope that this novel mutation will provide valuable information relevant to the modification of carotenoid content in crops.