Carotenoid Metabolism in Plants: The Role of Plastids

Abstract

Carotenoids are indispensable to plants and critical in human diets. Plastids are the organelles for carotenoid biosynthesis and storage in plant cells. They exist in various types, which include proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. These plastids have dramatic differences in their capacity to synthesize and sequester carotenoids. Clearly, plastids play a central role in governing carotenogenic activity, carotenoid stability, and pigment diversity. Understanding of carotenoid metabolism and accumulation in various plastids expands our view on the multifaceted regulation of carotenogenesis and facilitates our efforts toward developing nutrient-enriched food crops. In this review, we provide a comprehensive overview of the impact of various types of plastids on carotenoid biosynthesis and accumulation, and discuss recent advances in our understanding of the regulatory control of carotenogenesis and metabolic engineering of carotenoids in light of plastid types in plants. Plastids, the sites for carotenoid biosynthesis and storage, play a central role in governing carotenogenic activity, carotenoid stability, and pigment diversity in plants. This review provides a comprehensive overview of the impact of various plastids on carotenoid biosynthesis and accumulation, as well as the effect of plastid types on the multifaceted regulation of carotenoid metabolism and metabolic engineering of carotenoids.