Plant carotenoids: genomics meets multi-gene engineering.

Carotenoids are present in plant photosynthetic tissues, where they have essential roles in photoreception and photoprotection, as well as in non-photosynthetic tissues, where they act as colorants, precursors for plant isoprenoid volatiles and signaling molecules (abscisic acid and strigolactones), nutritional antioxidants and vitamin A precursors. This review presents the recent advances in our understanding of their biosynthesis, the key metabolic steps controlling their accumulation in plant non-photosynthetic tissues and their metabolic engineering using multi-gene approaches.