Abstract
Members of the genus Lesquerella produce seed oil that contains a high proportion of hydroxy fatty acids (HFAs). There are three groups of Lesquerella species that are distinguished by their most abundant seed oil fatty acid: lesquerolic acid (20:1OH; e.g. Lesquerella fendleri), densipolic acid (18:2OH; e.g. Lesquerella kathryn), and auricolic acid (20:2OH; e.g. Lesquerella auriculata). To investigate the biochemistry of HFA production in Lesquerella species, the conversion of putative radiolabeled intermediates of HFA biosynthesis, including 18:1, 20:1,18:1OH, 18:2OH, and 20:1OH, was examined in developing embryos of L. fendleri, L.kathryn, and L. auriculata. The results are consistent with (a) 18:1OH formation by hydroxylation of 18:1, (b) elongation and desaturation of 18:1OH to produce 20:1OH and 18:2OH, respectively, and (c) desaturation of 20:1OH to produce 20:2OH. The desaturation of 20:1OH was also found to occur in developing embryos of high, but not low, linolenic acid flax. This suggests that the desaturation is catalyzed by the extraplastidial linoleate desaturase. Confirming this suggestion, it was notable that 18:1OH and 18:2OH were found in low and high linolenic flax (Linum usitatissimum) seeds, respectively, at levels of 0.2 to 1%.
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Selected References
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- Covello P. S., Reed D. W. Functional expression of the extraplastidial Arabidopsis thaliana oleate desaturase gene (FAD2) in Saccharomyces cerevisiae. Plant Physiol. 1996 May;111(1):223–226. doi: 10.1104/pp.111.1.223. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Taylor D. C., Barton D. L., Rioux K. P., Mackenzie S. L., Reed D. W., Underhill E. W., Pomeroy M. K., Weber N. Biosynthesis of Acyl Lipids Containing Very-Long Chain Fatty Acids in Microspore-Derived and Zygotic Embryos of Brassica napus L. cv Reston. Plant Physiol. 1992 Aug;99(4):1609–1618. doi: 10.1104/pp.99.4.1609. [DOI] [PMC free article] [PubMed] [Google Scholar]
- van de Loo F. J., Broun P., Turner S., Somerville C. An oleate 12-hydroxylase from Ricinus communis L. is a fatty acyl desaturase homolog. Proc Natl Acad Sci U S A. 1995 Jul 18;92(15):6743–6747. doi: 10.1073/pnas.92.15.6743. [DOI] [PMC free article] [PubMed] [Google Scholar]