Abstract
Oil bodies isolated from the mature seeds of rape (Brassica napus L.), mustard (Brassica juncea L.), cotton (Gossypium hirsutum L.), flax (Linus usitatis simum), maize (Zea mays L.), peanut (Arachis hypogaea L.), and sesame (Sesamum indicum L.) had average diameters that were different but within a narrow range (0.6-2.0 [mu]m), as measured from electron micrographs of serial sections. Their contents of triacylglycerols (TAG), phospholipids, and proteins (oleosins) were correlated with their sizes. The correlation fits a formula that describes a spherical particle surrounded by a shell of a monolayer of phospholipids embedded with oleosins. Oil bodies from the various species contained substantial amounts of the uncommon negatively charged phosphatidylserine and phosphatidylinositol, as well as small amounts of free fatty acids. These acidic lipids are assumed to interact with the basic amino acid residues of the oleosins on the surface of the phospholipid layer. Isoelectrofocusing revealed that the oil bodies from the various species had an isoelectric point of 5.7 to 6.6 and thus possessed a negatively charged surface at neutral pH. We conclude that seed oil bodies from diverse species are very similar in structure. In rapeseed during maturation, TAG and oleosins accumulated concomitantly. TAG-synthesizing acyltransferase activities appeared at an earlier stage and peaked during the active period of TAG accumulation. The concomitant accumulation of TAG and oleosins is similar to that reported earlier for maize and soybean, and the finding has an implication for the mode of oil body synthesis during seed maturation.
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Selected References
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- Cao Y. Z., Huang A. H. Acyl coenzyme a preference of diacylglycerol acyltransferase from the maturing seeds of cuphea, maize, rapeseed, and canola. Plant Physiol. 1987 Jul;84(3):762–765. doi: 10.1104/pp.84.3.762. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Murphy D. J., Cummins I., Kang A. S. Synthesis of the major oil-body membrane protein in developing rapeseed (Brassica napus) embryos. Integration with storage-lipid and storage-protein synthesis and implications for the mechanism of oil-body formation. Biochem J. 1989 Feb 15;258(1):285–293. doi: 10.1042/bj2580285. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Murphy D. J., Keen J. N., O'Sullivan J. N., Au D. M., Edwards E. W., Jackson P. J., Cummins I., Gibbons T., Shaw C. H., Ryan A. J. A class of amphipathic proteins associated with lipid storage bodies in plants. Possible similarities with animal serum apolipoproteins. Biochim Biophys Acta. 1991 Jan 17;1088(1):86–94. doi: 10.1016/0167-4781(91)90156-g. [DOI] [PubMed] [Google Scholar]
- Nixon M., Chan S. H. A simple and sensitive colorimetric method for the determination of long-chain free fatty acids in subcellular organelles. Anal Biochem. 1979 Sep 1;97(2):403–409. doi: 10.1016/0003-2697(79)90093-9. [DOI] [PubMed] [Google Scholar]
- Qu R. D., Huang A. H. Oleosin KD 18 on the surface of oil bodies in maize. Genomic and cDNA sequences and the deduced protein structure. J Biol Chem. 1990 Feb 5;265(4):2238–2243. [PubMed] [Google Scholar]
- Qu R., Wang S. M., Lin Y. H., Vance V. B., Huang A. H. Characteristics and biosynthesis of membrane proteins of lipid bodies in the scutella of maize (Zea mays L.). Biochem J. 1986 Apr 1;235(1):57–65. doi: 10.1042/bj2350057. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smith P. K., Krohn R. I., Hermanson G. T., Mallia A. K., Gartner F. H., Provenzano M. D., Fujimoto E. K., Goeke N. M., Olson B. J., Klenk D. C. Measurement of protein using bicinchoninic acid. Anal Biochem. 1985 Oct;150(1):76–85. doi: 10.1016/0003-2697(85)90442-7. [DOI] [PubMed] [Google Scholar]
- Sun C., Cao Y. Z., Huang A. H. Acyl coenzyme a preference of the glycerol phosphate pathway in the microsomes from the maturing seeds of palm, maize, and rapeseed. Plant Physiol. 1988 Sep;88(1):56–60. doi: 10.1104/pp.88.1.56. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tzen J. T., Huang A. H. Surface structure and properties of plant seed oil bodies. J Cell Biol. 1992 Apr;117(2):327–335. doi: 10.1083/jcb.117.2.327. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tzen J. T., Lai Y. K., Chan K. L., Huang A. H. Oleosin isoforms of high and low molecular weights are present in the oil bodies of diverse seed species. Plant Physiol. 1990 Nov;94(3):1282–1289. doi: 10.1104/pp.94.3.1282. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tzen J. T., Lie G. C., Huang A. H. Characterization of the charged components and their topology on the surface of plant seed oil bodies. J Biol Chem. 1992 Aug 5;267(22):15626–15634. [PubMed] [Google Scholar]
- Vance V. B., Huang A. H. The major protein from lipid bodies of maize. Characterization and structure based on cDNA cloning. J Biol Chem. 1987 Aug 15;262(23):11275–11279. [PubMed] [Google Scholar]
- Wang S. M., Huang A. H. Biosynthesis of lipase in the scutellum of maize kernel. J Biol Chem. 1987 Feb 15;262(5):2270–2274. [PubMed] [Google Scholar]
- Yatsu L. Y., Jacks T. J. Spherosome membranes: half unit-membranes. Plant Physiol. 1972 Jun;49(6):937–943. doi: 10.1104/pp.49.6.937. [DOI] [PMC free article] [PubMed] [Google Scholar]