, Volume 220, Issue 5, pp 785–793

ζ-Carotene cis isomers as products and substrates in the plant poly-cis carotenoid biosynthetic pathway to lycopene

Original Article

DOI: 10.1007/s00425-004-1395-2

Cite this article as:
Breitenbach, J. & Sandmann, G. Planta (2005) 220: 785. doi:10.1007/s00425-004-1395-2


The plant carotenoid biosynthetic pathway to cyclic carotenes proceeds via carotene precursors in cis configuration. Involvement of individual isomers was elucidated by genetic complementation of desaturations and in vitro reactions of the corresponding enzyme. Determination of substrate and product specificity of phytoene and ζ-carotene desaturase revealed that 15-cis-phytoene is converted to 9,15,9′-tricis-ζ-carotene with 15,9′-dicis-phytofluene as intermediate by the first desaturase. Prior to a subsequent conversion by ζ-carotene desaturase, the 15-cis double bond of 9,15,9′-tricis-ζ-carotene has to be (photo)isomerized to all-trans. Then, the resulting 9,9′-dicis-ζ-carotene is utilized by ζ-carotene desaturase via 7,9,9′-tricis-neurosporene to 7,9,7′,9′-tetracis-lycopene. Other ζ-carotene isomers that are assumed to be spontaneous isomerization products were not converted, except for the asymmetric 9-cis-ζ-carotene. This isomer is desaturated only to 7,9-dicis-neurosporene resembling a dead-end of the pathway. Prolycopene, the product of the desaturation reactions, is finally isomerized by a specific isomerase to all-trans-lycopene, which is a prerequisite for cyclization to β-carotene. The 5-cis-lycopene and the 9-cis-and 13-cis-β-carotene isomers detected in leaves are thought to originate independently from cis precursors by non-enzymatic isomerization of their all-trans forms.


Capsicumζ-Carotene desaturaseζ-Carotene isomersGentianaPoly-cis carotenoidsPhytoene desaturase





Phytoene desaturase




ζ-Carotene desaturase



Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  1. 1.Biosynthesis Group, Department of Botany 213J.W. Goethe UniversityFrankfurtGermany