An alternative pathway to beta -carotene formation in plant chromoplasts discovered by map-based cloning of beta and old-gold color mutations in tomato.

ABSTRACT: Carotenoid pigments in plants fulfill indispensable functions in photosynthesis. Carotenoids that accumulate as secondary metabolites in chromoplasts provide distinct coloration to flowers and fruits. In this work we investigated the genetic mechanisms that regulate accumulation of carotenoids as secondary metabolites during ripening of tomato fruits. We analyzed two mutations that affect fruit pigmentation in tomato (Lycopersicon esculentum): Beta (B), a single dominant gene that increases beta-carotene in the fruit, and old-gold (og), a recessive mutation that abolishes beta-carotene and increases lycopene. Using a map-based cloning approach we cloned the genes B and og. Molecular analysis revealed that B encodes a novel type of lycopene beta-cyclase, an enzyme that converts lycopene to

SUBMITTER: Ronen G 

PROVIDER: S-EPMC27155 | biostudies-literature | 2000 Sep

REPOSITORIES: biostudies-literature