Or gene and its use in manipulating carotenoid content and composition in plants and other organisms

US8071841B2 · kind B2 · utility

Assignee

• The United States of America, as represented by the Secretary of Agriculture · US

Inventors

• Li Li · Stanford, US
• Joyce Van Eck · Ithaca, US

Key dates

• Filing date: Dec 14, 2006
• Grant date: Dec 6, 2011
• Expiry date: Jun 15, 2030

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C12N15/825
• WIPO field: Biotechnology
• WIPO sector: Chemistry

Abstract

The cauliflower (Brassica oleracea L. var. botrytis) Or gene is a semi-dominant, single-locus mutation. It induces the accumulation of high levels of beta-carotene in various tissues that are normally devoid of carotenoids, turning them orange. Using a map-based cloning strategy, we identified a single gene representing Or and successfully verified its identity by functional complementation in the wild type cauliflower. The Or gene encodes a plastid membrane protein containing the DnaJ zinc figure domain. A likely gain-of-function mutation from a 4.3-kb retrotransposon insertion in the Or allele confers the orange phenotype in the mutant. Southern blot analysis revealed that Or is a single-copy sequence in the cauliflower genome. High level of expression of the Or gene and the protein was found in very young leaves, curds, and flowers at comparable abundance between wild type and the Or mutant. Or likely functions in regulating the differentiation of some non-photosynthetic plastids into chromoplasts, which provide the deposition “sink” for carotenoid accumulation. Successful demonstration of Or in conferring carotenoid accumulation in potato tubers indicates its potential use to i…