Abstract
Carotenoids are important pigments accumulated in large amounts in tomato fruit. The first step of carotenogenesis is catalyzed by the fruit-specific enzyme PSY1 (PHYTOENE SYNTHASE 1) and leads to the formation of phytoene from geranyl geranyl diphosphate (GGPP). This is the rate-limiting step of the pathway, precisely because it provides the first carotenoid, and also by the competition …