The plants' 1-deoxy-D-xylulose-5-phosphate pathway for biosynthesis of isoprenoids

Isoprenoid biosynthesis in plants proceeds via two independent pathways: 1) the cytosolic classical acetate/mevalonate pathway (biosynthesis of sterols, sesquiterpenes, triterpenoids) and 2) via the non-mevalonate 1-deoxy-D-xylulose-5-phosphate (DOX-P) pathway for the biosynthesis of plastidic isoprenoids such as carotenoids, phytol (side-chain of chlorophylls), plastoquinone-9, isoprene, mono- and diterpenes. Both pathways form isopentenyl-diphosphate (IPP) as precursors, from which all other isoprenoids are formed via head-to-tail addition. The present knowledge of the novel 1-deoxy-D-xylulose-5-phosphate (DOX-P) pathways for isopentenyl-diphosphate biosynthesis, which is apparently located in plastids, is reviewed in this contribution. It provides a new insight into chloroplast metabolism.