Abstracts now available online - Euro Fed Lipid

Transgenic Oilseeds as a New Renewable Source for Very Long Chain
Polyunsaturated Fatty acids
Amine Abbadi 1,2 , Frédéric Domergue 3 , Ivo Feussner 1 and Ernst Heinz 3
1
Albrecht-von-Haller Institute for Plant Science, University of Göttingen,
D-37077 Göttingen, Germany, aabbadi@gwdg.de
2
Norddeutsche Pflanzenzucht Hans-Georg Lembke KG, Hohenlieth, D-24363 Holtsee,
Germany
3
Biozentrum klein Flottbek, University of Hamburg, D-22609 Hamburg, Germany
A constant supply of very long-chain polyunsaturated fatty acids (VLCPUFAs) such as
arachidonic (ARA), eicosapentaenoic (EPA), and docosahexaenoic acid (DHA) as part
of the human diet is considered beneficial. These ω6- and ω3-fatty acids function as
constituents of membrane phospholipids and as precursors of different classes of
eicosanoids. VLCPUFA biosynthesis starts from linoleic and α-linolenic acids. They are
not present in reserve triacylglycerols of angiosperm plants and, therefore, enter the
human diet mainly in the form of marine and freshwater fish. In view of the increasing
world population and the problem of over fishing marine resources, transgenic oilseeds
might constitute a sustainable source of VLCPUFAs. To establish VLCPUFA
biosynthesis by genetic engineering of annual oilseed crops additional fatty acyldesaturases,
elongases and acyltransferases are required that have regiospecificities
not present in agronomically important plants. As a result of parallel efforts in several
laboratories, cDNAs for all the desaturases and elongases required for the conversion
of linoleic and α-linolenic acid to ARA, EPA and DHA are available from different
organisms. Heterologous expression of appropriate ensembles in different plants has
resulted in the production of dietary significant amounts of ARA and EPA in transgenic
seed oils. The results of these strategies will be discussed.