title: Chromoplasts of Tropaeolum majus L.: Lipid synthesis in whole organelles and subfractions.
abstract: Isolation of tubulous chromoplasts from Tropaeolum majus L. petals was achieved in pure form. Their main substructures-lipid bodies, tubules, and envelope membranes-have been enriched. Whole chromoplasts as well as substructures have been tested for their activities in lipid synthesis. The following activities were found: fatty acid synthesis from acetate, glycosyl transfer reactions from UDP-galactose and UDP-glucose to galactolipids and sterols, acyltransferase reactions from palmitoyl-CoA, and a very active acyl-CoA hydrolase (EC 3.1.2.2.). Fatty acid synthesis was restricted to whole chromoplasts. Glycosyl- and acyltransferases were essentially confined to envelope membranes, whereas acyl-CoA hydrolase was found in all fractions. The chemical composition of chromoplast subfractions was determined. The lipid bodies consisted mainly of galactolipids and carotenoid esters in a 1:1 ratio, together with small amounts of protein.
authors.affiliation: Lehrstuhl für Zellbiologie, Institut für Biologie II, Schänzlestraße 1, D-7800, Freiburg, Federal Republic of Germany.
authors.forename: B
authors.initials: B
authors.lastname: Liedvogel
authors.forename: H
authors.initials: H
authors.lastname: Kleinig
authors.forename: J A
authors.initials: JA
authors.lastname: Thompson
authors.forename: H
authors.initials: H
authors.lastname: Falk