Abstract
The overall fatty acid composition of leaf lipids in a mutant of Arabidopsis thaliana was characterized by elevated amounts of palmitic acid and a decreased amount of unsaturated 16-carbon fatty acids as a consequence of a single nuclear mutation. Quantitative analysis of the fatty acid composition of individual lipids suggested that the mutant is deficient in the activity of a chloroplast ω9 fatty acid desaturase which normally introduces a double bond in 16-carbon acyl chains esterified to monogalactosyldiacylglycerol (MGD). The mutant exhibited an increased ratio of 18- to 16-carbon fatty acids in MGD due to a change in the relative contribution of the prokaryotic and eukaryotic pathways of lipid biosynthesis. This appears to be a regulated response to the loss of chloroplast ω9 desaturase and presumably reflects a requirement for polyunsaturated fatty acids for the normal assembly of chloroplast membranes. The reduction in mass of prokaryotic MGD species involved both a reduction in synthesis of MGD by the prokaryotic pathway and increased turnover of MGD molecular species which contain 16:0.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Browse J., Kunst L., Anderson S., Hugly S., Somerville C. A mutant of Arabidopsis deficient in the chloroplast 16:1/18:1 desaturase. Plant Physiol. 1989 Jun;90(2):522–529. doi: 10.1104/pp.90.2.522. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Browse J., McCourt P. J., Somerville C. R. Fatty acid composition of leaf lipids determined after combined digestion and fatty acid methyl ester formation from fresh tissue. Anal Biochem. 1986 Jan;152(1):141–145. doi: 10.1016/0003-2697(86)90132-6. [DOI] [PubMed] [Google Scholar]
- Browse J., McCourt P., Somerville C. R. A mutant of Arabidopsis lacking a chloroplast-specific lipid. Science. 1985 Feb 15;227(4688):763–765. doi: 10.1126/science.227.4688.763. [DOI] [PubMed] [Google Scholar]
- Browse J., McCourt P., Somerville C. A mutant of Arabidopsis deficient in c(18:3) and c(16:3) leaf lipids. Plant Physiol. 1986 Jul;81(3):859–864. doi: 10.1104/pp.81.3.859. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Browse J., Warwick N., Somerville C. R., Slack C. R. Fluxes through the prokaryotic and eukaryotic pathways of lipid synthesis in the '16:3' plant Arabidopsis thaliana. Biochem J. 1986 Apr 1;235(1):25–31. doi: 10.1042/bj2350025. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cho S. H., Thompson G. A., Jr On the metabolic relationships between monogalactosyldiacylglycerol and digalactosyldiacylglycerol molecular species in Dunaliella salina. J Biol Chem. 1987 Jun 5;262(16):7586–7593. [PubMed] [Google Scholar]
- Goldberg I. J., Le N. A., Leeman B., Brown W. V., Lindgren F. T. Evidence for heterogeneity of low-density lipoprotein metabolism in the cynomolgus monkey. Biochim Biophys Acta. 1986 Nov 14;879(2):179–185. doi: 10.1016/0005-2760(86)90101-3. [DOI] [PubMed] [Google Scholar]
- Howling D., Morris L. J., Gurr M. I., James A. T. The specificity of fatty acid desaturases and hydroxylases. The dehydrogenation and hydroxylation of monoenoic acids. Biochim Biophys Acta. 1972 Jan 27;260(1):10–19. doi: 10.1016/0005-2760(72)90068-9. [DOI] [PubMed] [Google Scholar]
- Khan M. U., Williams J. P. Improved thin-layer chromatographic method for the separation of major phospholipids and glycolipids from plant lipid extracts and phosphatidyl glycerol and bis(monoacylglyceryl) phosphate from animal lipid extracts. J Chromatogr. 1977 Oct 11;140(2):179–185. doi: 10.1016/s0021-9673(00)88412-5. [DOI] [PubMed] [Google Scholar]
- Kunst L., Browse J., Somerville C. Altered regulation of lipid biosynthesis in a mutant of Arabidopsis deficient in chloroplast glycerol-3-phosphate acyltransferase activity. Proc Natl Acad Sci U S A. 1988 Jun;85(12):4143–4147. doi: 10.1073/pnas.85.12.4143. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McKeon T. A., Stumpf P. K. Purification and characterization of the stearoyl-acyl carrier protein desaturase and the acyl-acyl carrier protein thioesterase from maturing seeds of safflower. J Biol Chem. 1982 Oct 25;257(20):12141–12147. [PubMed] [Google Scholar]
- Norman H. A., John J. B. Differential Effects of a Substituted Pyridazinone, BASF 13-338, on Pathways of Monogalactosyldiacylglycerol Synthesis in Arabidopsis. Plant Physiol. 1987 Nov;85(3):684–688. doi: 10.1104/pp.85.3.684. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Roughan P. G., Mudd J. B., McManus T. T., Slack C. R. Linoleate and alpha-linolenate synthesis by isolated spinach (Spinacia oleracea) chloroplasts. Biochem J. 1979 Dec 15;184(3):571–574. doi: 10.1042/bj1840571. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Slack C. R., Roughan P. G., Terpstra J. Some properties of a microsomal oleate desaturase from leaves. Biochem J. 1976 Apr 1;155(1):71–80. doi: 10.1042/bj1550071. [DOI] [PMC free article] [PubMed] [Google Scholar]