Oil body formation

DGAT O. tauri S. cerevisiae H1246 (TAG-deficient quadmple mutant) Restoration of TAG bioqmthesis Oil body formation in yeast... 

Seed oil bodies in plants are surrounded by a monolayer of highly imusual and abundant proteins, the oleosins, which can comprise as much as 8-15% total seed protein [1,2]. However, relatively little is known about the subcellular targeting and processing of oleosins, and their role in oil-body formation and maturation. We have expressed a soybean 24 kDa oleosin in transgenic rapeseed, in order to elucidate these issues. Detailed experimental data will be published elsewhere [3], but in this report, we discuss the implications of our findings for the mechanism of oil-body ontogeny in plants. 

Sarmiento, C. et al (1996) Expression and subcellular targeting of a soybean oleosin in transgenic rapeseed. Implications for the mechanism of oil body formation in seeds. Submitted for publication. 

Murphy, D.J., Cummins, I. and Kang, A.S. (1989) 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. 258, 285-293. 

Fig.4 Model for oil-body formation. (A) Assembly of triacylglycerols on ER, (B) Sectretion and coalescence of small oil droplets, (C) Assembly of olein on oil-body boundary, (D) Appearance of mature oil-bodies with osmiophilic coat containing olein.

Fig.4 for oil-body formation in crucifers, and perhaps in other oilseeds. 

Ouyang, L.-L., Chen, S.-H., li, Y, Zhou, Z.-G., 2013. Transcriptome analysis reveals unique G4-Kke photosynthesis and oil body formation in an arachidonic acid-rich microalga Myrmecia incisa Reisigl H4301. BMC Genomics... 

Absorption route Can enter the body by halation or ingestion. Harmful atmospheric concentrations can buid up fairly rapidy on evaporation at >prox. 2(7 C - even more rapidly in aerosol form. knmedMe ellecis Irritotes the eyes, skin and respiratory tract. Liquid destroys the skin s natural oils. cause formation of carboj hemoglobin. Effects of protengod/repoalodmqtoeMro Can affect the blood. Can dam the liver. In serious cases risk of unconsciousness. ... 

According to this model, oleosins are not required for TAG formation and oil-body biogenesis, but the relative rate of oleosin biosynthesis and accumulation on oil-body surfaces during the entire period of seed development will be the major determinant of the final size of oil bodies in mature seeds. This model is consistent with all published data relating to oleosin biosynthesis and oil-body ontogeny. 

Bergfeld, R., Hong, Y.N., Kuhnl, T. and Schopfer, P. (1978) Formation of oleosomes (storage oil bodies) during embryogenesis and their breakdown during seedling development in cotyledons of Sinapsis alba L. Plants 143 297-303. 

The cleaning process proceeds by one of three primary mechanisms solubilization, emulsification, and roll-up [229]. In solubilization the oily phase partitions into surfactant micelles that desorb from the solid surface and diffuse into the bulk. As mentioned above, there is a body of theoretical work on solubilization [146, 147] and numerous experimental studies by a variety of spectroscopic techniques [143-145,230]. Emulsification involves the formation and removal of an emulsion at the oil-water interface the removal step may involve hydrodynamic as well as surface chemical forces. Emulsion formation is covered in Chapter XIV. In roll-up the surfactant reduces the contact angle of the liquid soil or the surface free energy of a solid particle aiding its detachment and subsequent removal by hydrodynamic forces. Adam and Stevenson s beautiful photographs illustrate roll-up of lanoline on wood fibers [231]. In order to achieve roll-up, one requires the surface free energies for soil detachment illustrated in Fig. XIII-14 to obey... 

When treated with alcoholic solution of ammonia, it yields thio-sinamine (allyl thiourea), of the formula C3H5. NH. CS. NHj. This body melts at 74°. The formation of this body forms the basis for a method of its determination, which, with other methods, will be found fully described under Oil of Mustard (Vol. I, p. 474). 

Flow properties of macroemulsions are different from those of non-emulsified phases 19,44). When water droplets are dispersed in a non-wetting oil phase, the relative permeability of the formation to the non-wetting phase decreases. Viscous energy must be expended to deform the emulsified water droplets so that they will pass through pore throats. If viscous forces are insufficient to overcome the capillary forces which hold the water droplet within the pore body, flow channels will become blocked with persistent, non-draining water droplets. As a result, the flow of oil to the wellbore will also be blocked. 

Since Thin Film Spreading Agents do not produce ultralow interfacial tensions, capillary forces can trap oil in pore bodies even though the oil has been displaced from the surface of the porous medium. Therefore, recovery of incremental oil is dependent on the formation of an oil bank. Muggee, F. D. U.S. Patent 3 396 792, 1968. 

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