A. Parry, R. Horgan
1991
Citations
0
Influential Citations
55
Citations
Journal
Phytochemistry
Abstract
Abstract The conversion of all-trans-violaxanthin to 9′-cis-neoxanthin was shown to occur in fluridone-treated etiolated Lycopersicon and Phaseolus seedlings, following exposure to light. The results of deuterium oxide labelling experiments supported this precursor/product relationship, and provided further evidence for the origin of abscisic acid. Several apo-carotenoids, putative by-products of abscisic acid biosynthesis, were synthesised by chemical oxidation but were not detected in plant extracts. In vitro, lipoxygenase cleaved neoxanthin and violaxanthin down to small ( \ C13) fragments. It may be that in vivo any apo-carotenoids formed by the specific cleavage of 9′-cis-neoxanthin, during abscisic acid biosynthesis, are rapidly metabolized by lipoxygenase or similar enzymes.