Abstract
A mutation at the fab2 locus of Arabidopsis caused increased levels of stearate in leaves. The increase in leaf stearate in fab2 varied developmentally, and the largest increase occurred in young leaves, where stearate accounted for almost 20% of total leaf fatty acids. The fatty acid composition of leaf lipids isolated from the fab2 mutant showed increased stearate in all the major glycerolipids of both the chloroplast and extrachloroplast membranes. Although the stearate content was increased, the fab2 mutant still contained abundant amounts of 18:1, 18:2, and 18:3 fatty acids. These results are consistent with the expectations for a mutation partially affecting the action of the stromal stearoyl-acyl carrier protein desaturase. Positional analysis indicated that the extra 18:0 is excluded with high specificity from the sn-2 position of both chloroplast and extrachloroplast glycerolipids. Although stearate content was increased in all the major leaf membrane lipids, the amount of increase varied considerably among the different lipids, from a high of 25% of fatty acids in phosphatidylcholine to a low of 2.9% of fatty acids in monogalactosyldiacylglycerol.
Full Text
The Full Text of this article is available as a PDF (889.7 KB).
Selected 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]
- Hajra A. K. On extraction of acyl and alkyl dihydroxyacetone phosphate from incubation mixtures. Lipids. 1974 Aug;9(8):502–505. doi: 10.1007/BF02532495. [DOI] [PubMed] [Google Scholar]
- Knutzon D. S., Thompson G. A., Radke S. E., Johnson W. B., Knauf V. C., Kridl J. C. Modification of Brassica seed oil by antisense expression of a stearoyl-acyl carrier protein desaturase gene. Proc Natl Acad Sci U S A. 1992 Apr 1;89(7):2624–2628. doi: 10.1073/pnas.89.7.2624. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kunst L., Browse J., Somerville C. A mutant of Arabidopsis deficient in desaturation of palmitic Acid in leaf lipids. Plant Physiol. 1989 Jul;90(3):943–947. doi: 10.1104/pp.90.3.943. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Murata N., Yamaya J. Temperature-dependent phase behavior of phosphatidylglycerols from chilling-sensitive and chilling-resistant plants. Plant Physiol. 1984 Apr;74(4):1016–1024. doi: 10.1104/pp.74.4.1016. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ohlrogge J. B., Kuo T. M. Plants have isoforms for acyl carrier protein that are expressed differently in different tissues. J Biol Chem. 1985 Jul 5;260(13):8032–8037. [PubMed] [Google Scholar]
- Okuley J., Lightner J., Feldmann K., Yadav N., Lark E., Browse J. Arabidopsis FAD2 gene encodes the enzyme that is essential for polyunsaturated lipid synthesis. Plant Cell. 1994 Jan;6(1):147–158. doi: 10.1105/tpc.6.1.147. [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]
- Shanklin J., Somerville C. Stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs. Proc Natl Acad Sci U S A. 1991 Mar 15;88(6):2510–2514. doi: 10.1073/pnas.88.6.2510. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shimakata T., Stumpf P. K. The procaryotic nature of the fatty acid synthetase of developing Carthamus tinctorius L. (Safflower) seeds. Arch Biochem Biophys. 1982 Aug;217(1):144–154. doi: 10.1016/0003-9861(82)90488-x. [DOI] [PubMed] [Google Scholar]
- Simpson E. E., Williams J. P. Galactolipid Synthesis in Vicia faba Leaves: IV. Site(s) of Fatty Acid Incorporation into the Major Glycerolipids. Plant Physiol. 1979 Apr;63(4):674–676. doi: 10.1104/pp.63.4.674. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Slack C. R., Roughan P. G., Balasingham N. Labelling studies in vivo on the metabolism of the acyl and glycerol moieties of the glycerolipids in the developing maize leaf. Biochem J. 1977 Feb 15;162(2):289–296. doi: 10.1042/bj1620289. [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]
- Slack C. R., Roughan P. G. The kinetics of incorporation in vivo of (14C)acetate and (14C)carbon dioxide into the fatty acids of glycerolipids in developing leaves. Biochem J. 1975 Nov;152(2):217–228. doi: 10.1042/bj1520217. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams J. P., Watson G. R., Leung S. P. Galactolipid Synthesis in Vicia faba Leaves: II. Formation and Desaturation of Long Chain Fatty Acids in Phosphatidylcholine, Phosphatidylglycerol, and the Galactolipids. Plant Physiol. 1976 Feb;57(2):179–184. doi: 10.1104/pp.57.2.179. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wu J., James D. W., Jr, Dooner H. K., Browse J. A Mutant of Arabidopsis Deficient in the Elongation of Palmitic Acid. Plant Physiol. 1994 Sep;106(1):143–150. doi: 10.1104/pp.106.1.143. [DOI] [PMC free article] [PubMed] [Google Scholar]