|GIBLIN, E. MICHAEL|
Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/11/2004
Publication Date: 2/1/2005
Citation: Jadhav, A., Marillia, E., Babic, V., Giblin, E., Cahoon, E.B., Kinney, A.J., Taylor, D.C. 2005. Production of 22:2 delta5, delta13 and 20:1 delta5 in Brassica carinata and soybean breeding lines via introduction of limnanthes genes. Molecular Breeding. 15:157-167.
Interpretive Summary: The seed oil of the meadowfoam plant contains large amounts of novel fatty acids that are highly desired by the lubricant and cosmetic industries. Meadowfoam, however, has limited potential for large scale production as an oilseed crop. As an alternative to the agronomic improvement of this plant, genes associated with the production of the novel fatty acids of meadowfoam seeds were transferred to the established crops soybean and Ethiopian mustard. The introduction of these genes resulted in the accumulation of substantial amounts of meadowfoam-type fatty acids in the seed oil of soybean and Ethiopian mustard. The findings of this study will be useful for molecular biologists and geneticists attempting to enhance the industrial value of existing oilseed crops. This research will ultimately expand the markets for oilseed crops grown by U.S. farmers and result in vegetable oils with greater utility for industrial chemists.
Technical Abstract: Seed oils of meadowfoam (Limnanthes douglasii, L. alba) contain very-long-chain fatty acids of strategic importance for a number of industrial applications. These include the mono-unsaturate 20:1delta5 and the di-unsaturate 22:2delta5,13. Engineering of meadowfoam-type oils in other oilseed crops is desirable for the production of these fatty acids as industrial feedstocks. Accordingly, we have targeted Brassica carinata and soybean (Glycine max) to trangenically engineer the biosynthesis of these novel fatty acids. An L. douglasii seed-specific cDNA (designated Des5) encoding a homolog of acyl-coenzyme A desaturases found in animals, fungi, and cyanobacteria was expressed in B. carinata, which resulted in accumulation of up to 10% 22:2delta5,13 in the seed oil. In soybean, co-expression of Des5 with a cDNA encoding an FAE1 (elongase complex condensing enzyme) homolog from L. douglasii resulted in the accumulation of 20:1delta5 to approximately 10% of the total fatty acids of seeds. The content of C20 and C22 fatty acids was also increased from <0.5% in non-transformed soybean seeds to >25% in seeds co-expressing the L. douglasii Des5 and FAE1 cDNAs. These results demonstrate the utility of B. carinata and soybean for the production of vegetable oils containing novel C20 and C22 fatty acids.