Carotenoids are isoprenoids of industrial and nutritional interest produced by all photosynthetic organisms,
including plants. Too often, the metabolic engineering of plant carotenogenesis has been obstructed
by our limited knowledge on how the endogenous pathway interacts with other related metabolic pathways,
particularly with those involved in the production of isoprenoid precursors. However, recent discoveries
are providing new insights into this field. All isoprenoids derive from prenyl diphosphate
precursors. In the case of carotenoids, these precursors are produced predominantly by the methylerythritol
4-phosphate (MEP) pathway in plants. This review focuses on the progress in our understanding of
how manipulation of the MEP pathway impacts carotenoid biosynthesis and on the discoveries underlining
the central importance of coordinating the supply of MEP-derived precursors with the biosynthesis of
carotenoids and other derived isoprenoids.