The biosynthesis of calendic acid, octadeca-(8E,10E, 12Z)-trienoic, acid, by developing marigold seeds: origins of (E,E,Z) and (Z,E,Z) conjugated triene acids in higher plants

Using an homogenate of marigold seeds, gathered 15 days after flower-drop, [1-14C] linoleic acid and [1-14C] oleic acid were incorporated into calendic acid with little randomisation of the label. [1-14C] Linolenic acid was not incorporated. Despite requiring 12,13-dehydrogenation to form linoleic acid, the putative precursor, oleic acid was better incorporated than administered linoleic acid. Stearic acid, requiring both 12,13- and 9,10-dehydrogenation, was a poor precursor. The results of a series of double-labelling experiments support and supplement these conclusions.