|Mullen, Robert - UNIV OF GUELPH|
Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: May 23, 2004
Publication Date: May 27, 2004
Citation: Shockey, J.M., Dyer, J.M., Chapital, D.C., Kuan, J.W., Mullen, R.T., Cary, J.W. 2004. Cloning and characterization of a lysophosphatidic acid acyltransferase from tung (aleurities fordii)(abstract). American Society of Microbiology. Technical Abstract: The plant kingdom contains many examples of oil-producing seeds that contain triacylglycerols (TAG) enriched in novel, industrially useful fatty acids. However, many of these plant species are agronomically unsuited for industrial-scale growth and processing. The tung tree (Aleurites fordii) is one such example. The TAG fraction of tung seeds contains over 80% eleostearic acid (18:3 delta 9cis,11trans,13trans). The conjugated double bond structure of this unusual fatty acid makes tung oil a valuable commodity in the production of coatings, polymers, and inks; therefore, the ability to produce TAGs containing high levels of eleostearate in common temperate oilseed crops such as soybean or rapeseed is highly desirable. Our laboratory is addressing this task by engineering various components of the tung oil biosynthetic pathway in transgenic organisms and analyzing the effects on lipid metabolism. Full-length cDNA clones for lysophosphatidic acid acyltransferase, a key enzyme in the TAG biosynthetic pathway, have been isolated from both tung and Arabidopsis thaliana, an oilseed plant that does not synthesize eleostearic acid. The substrate specificities of these two enzymes will be compared by in vitro assay after overexpression in an LPAAT-deficient mutant of Escherichia coli. Subcellular targeting and effects on eleostearic acid content in total cellular TAG will also by examined by expression in baker's yeast (Saccharomyces cerevisiae) and Arabidopsis thaliana.