Incorporation of 1‐deoxy‐d‐xylulose into isoprene and phytol by higher plants and algae

Abstract

In further substantiating the novel mevalonate‐independent pathway for isoprenoid biosynthesis, which generates isopentenyl diphosphate (IPP) via 1‐deoxy‐d‐xylulose‐5‐phosphate, labeling experiments with 1‐[²H₁]deoxy‐d‐xylulose were performed with various higher plants and algae: efficient incorporation was observed into isoprene emitted by Populus, Chelidonium, and Salix, into the phytol moiety of chlorophylls in a red alga (Cyanidium), in two green algae (Scenedesmus, Chlamydomonas), and a higher plant (Lemna). By contrast, ¹³C‐mevalonate applied was incorporated into isoprene and phytol to a much lower extent or not at all. This demonstrates that this `1‐deoxy‐d‐xylulose‐5‐phosphate pathway' for biosynthesis of plastidic isoprenoids is widely distributed in photosynthetic organisms.