This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (43) Citing Articles via Google Scholar Google Scholar Articles by Pollard, M. R. Articles by Stumpf, P. K. Search for Related Content PubMed PubMed Citation Articles by Pollard, M. R. Articles by Stumpf, P. K. Agricola Articles by Pollard, M. R. Articles by Stumpf, P. K.

Articles

Long Chain (C₂₀ and C₂₂) Fatty Acid Biosynthesis in Developing Seeds of Tropaeolum majus

AN IN VIVO STUDY ¹

Department of Biochemistry and Biophysics, University of California, Davis, California 95616

The storage triacylglycerols of nasturtium (Tropaeolum majus) seeds are composed principally of cis-11-eicosenoate and cis-13-docosenoate. To investigate the biosynthesis of these C₂₀ and C₂₂ fatty acids, developing seed tissue was incubated with various ¹⁴C-labeled precursors. Incubation with [1-¹⁴C]acetate produced primarily cis-11-[1-¹⁴C]eicosenoate and cis-13-[1,3-¹⁴C]docosenoate in the triacylglycerol fraction, the odd-carbon [U-¹⁴C]oleate also formed from [¹⁴C] acetate was in the polar lipid fraction. Kinetic data showed that this oleate was not channeled into cis-11-eicosenoate nor cis-13-docosenoate over a 24-hour period. Under suitable conditions, nasturtium seed could also produce [¹⁴C]stearate, [¹⁴C]eicosenoate, and [¹⁴C]docosenoate from [1-¹⁴C]acetate. The results are discussed in terms of the number of pathways producing fatty acids. From pool size and other considerations, the results can be rationalized only in terms of different de novo systems for oleate biosythesis, one supplying oleate for incorporation into phospholipids and the other supplying oleate for chain elongation and subsequent esterification into triacylglycerols. Because of the probable heterogeneous nature of the seed tissue, it is not known if these two systems are operating in different cell types, in the same cell type at different stages of development, or in the same cell type concurrently.

¹ This work was supported by Grant PCM76 01495 from the National Science Foundation administered by P. K. S.

This article has been cited by other articles:

				E. Mietkiewska, E. M. Giblin, S. Wang, D. L. Barton, J. Dirpaul, J. M. Brost, V. Katavic, and D. C. Taylor Seed-Specific Heterologous Expression of a Nasturtium FAE Gene in Arabidopsis Results in a Dramatic Increase in the Proportion of Erucic Acid Plant Physiology, September 1, 2004; 136(1): 2665 - 2675. [Abstract] [Full Text] [PDF]

				F. E. Dayan, I. A. Kagan, and A. M. Rimando Elucidation of the Biosynthetic Pathway of the Allelochemical Sorgoleone Using Retrobiosynthetic NMR Analysis J. Biol. Chem., August 1, 2003; 278(31): 28607 - 28611. [Abstract] [Full Text] [PDF]

				X. Bao, M. Pollard, and J. Ohlrogge The Biosynthesis of Erucic Acid in Developing Embryos of Brassica rapa Plant Physiology, September 1, 1998; 118(1): 183 - 190. [Abstract] [Full Text]