Lipid Synthesis and Ultrastructure of the Laticifers of Etiolated Euphorbia lathyris Seedlings

In 6–14-day-old etiolated seedlings of Euphorbia lashyrisa latex triterpene synthesis of 19 µg day^–1 wasrecorded. This production was proportional to stem growth. Laticiferdistribution in the cotyledons and stem was studied. In ultra-thinsections the occurrence of many mitochondria was observed. A¹⁴C-latex triterpene synthesis was measured after ¹⁴C-glucoseand ¹⁴C-sucrose uptake by the cotyledons in which most of the¹⁴C-triterpenes were synthesized. ¹⁴C-incorporation into theselipids from 1^–14C]glucose, 6-¹⁴C]glucose and 3,4^–14points to a glycolytic catabolism of glucose prior to terpenesynthesis. The possible involvement of mitochondria in thissynthesis is discussed. Euphorbia lathyris, triterpene synthesis, laticifer, latex, mitochondria, ultrastructure