Biosynthesis and engineering of carotenoids and apocarotenoids in plants: state of the art and future prospects.

Carotenoids and their apocarotenoid derivatives are isoprenoid molecules important for the primary and secondary metabolisms of plants and other living organisms, displaying also key health-related roles in humans and animals. Progress in the knowledge of the carotenoid pathway at the genetic, biochemical and molecular level, supported by successful genetic engineering examples for an increasing number of important plant crops have paved the way for precise molecular breeding of carotenoids. In this review, following a description of the general carotenoid pathway, select examples of plant species able to produce specialty carotenoids and apocarotenoids are illustrated. An update on plant carotenoid engineering is also provided for non-solanaceous crops and members of the Solanaceae family, by means of different strategies and making use of plant and bacterial genes.