1. Carotenoid Metabolism in Plants
Nazia Nisar, Li Li, Shan Lu, Nay Chi Khin, Barry J. Pogson 
Molecular Plant 
Volume 8, Issue 1, Pages (January 2015)
DOI: /j.molp
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2. Figure 1 Schematic Carotenoid Biosynthetic Pathway.
The pathway shows the primary steps found in nearly all plant species. The C40 carotenoid phytoene is derived by condensation of two molecules of the C20 GGPP, produced from IPP and DMAPP. Phytoene is converted into lycopene via a series of desaturation and isomerization. Lycopene is cyclized by β-LCY and ε-LCY or β-LCY to produce α-carotene or β-carotene. These carotenes are further hydroxylated to produce xanthophylls (e.g. lutein and zeaxanthin). The cleavage of β-carotene branch by CCDs and NCEDs produces various volatiles (e.g. β-citraurin, etc.) and phytohormones (strigolactones and abscisic acid). Arabidopsis mutants defective in carotenogenesis (cla1; altered chloroplast 1, clb5; chloroplast biogenesis 5, ccr1, and ccr2; carotenoid and chloroplast regulation-1 and 2, lut1, lut2, and lut5; lutein deficient-1, 2, and 5) are shown in red. β-LCY, β-cyclase; β-OHase, β-carotene hydroxylase; CCD, carotenoid cleavage dioxygenase; CRTISO, carotenoid isomerase; ; ε-LCY, ε-cyclase; ε-OHase, ε-carotene hydroxylase; GA3P, glyceraldehyde-3-phosphate; GGPPs, GGPP synthase; NCED, 9-cis-epoxycarotenoid dioxygenase; NXS, neoxanthin synthase; PDS, phytoene desaturase; PSY, phytoene synthase; SDG8, SET2 histone methyltransferase; VDE, violaxanthin de-epoxidase; ZDS, ζ-carotene desaturase; ZEP, zeaxanthin epoxidase; Z-ISO, ζ-carotene isomerase. Adapted from Cazzonelli et al. (2010a).
Molecular Plant 2015 8, 68-82DOI: ( /j.molp )
Copyright © 2015 The Author Terms and Conditions