The sensitivity of lipid rafts in plant cells to the influence of simulated microgravity

1Kordyum, EL, 1Klymenko, O, 1Bulavin, IV, 1Zhupanov, IV, 1Vorobyova, TM, 2Ruelland, E
1M.G. Kholodny Institute of Botany of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
2Institute of Ecology and Environmental Sciences, University Paris-Est Creteil, Paris, France
Space Sci.&Technol. 2018, 24 ;(4):48-58
Publication Language: Ukrainian
Plants as the sources of oxygen and food for astronauts have been recognized as a key component of Bioregenerative Life Support System. Biological membranes, first of all, the plasmalemma, can play a crucial role in the adaptation of plants to microgravity due to their properties and functions. The presence of functional domains called as the “lipid rafts” was proved in the plasmalemma. It is assumed that rafts modulate protein interactions and, thus, they are involved in numerous essential cell processes. The investigations of lipid rafts promote to understand the biochemical processes occurring in cell membranes in the norm and in response to stress.  
        Problematics of our study is the understanding a degree of gravisensitivity of basic cell processes and an adaptive potential of plants in the microgravity conditions that is extremely important for working out the technologies of plant cultivation in the  Bioregenerative Life Support System.  Objective of our study is to find out a degree of gravisensitivity of lipid rafts in plant cells on such indices as the composition and content of saturated and unsaturated fatty acids and sterols.
        Materials and methods are concerning with the pea seedlings, kind Bersek, which were growing during 6 days in the stationary conditions and under slow horizontal clinorotation. On the 7th day, the seedlings were cut off from the roots. A raft fraction was obtained from the plasmalemma fraction isolated from roots using a centrifuge “Оptima L-90K“. The raft fraction was investigated by the methods of electron microscopy with an electron microscope JEM 1230 (“JЕОL”, Japan) and gas chromatography using an apparatus HRGC 5300 (“Carlo Erba Instruments”, Italy). 
          It was shown that rafts look like thin ribbons 80–100 nm long and 6–13 nm wide. Under clinorotation, the qualitative composition of main fatty acids in the raft fraction did not change; the differences were found in their percentage. Under the influence of simulated microgravity, the content of saturated fatty acids was greater than the content of unsaturated fatty acids as well as it has been increased, especially a palmitic acid, both in the raft fraction and in the stationary control. Thereafter, a percent of unsaturated fatty acids decreased, especially arachidonic acid. A decrease in the content of monoenic unsaturated fatt acids in comparison with control was noted too. Content of a tetraenoic fatty acids has a highest percentage among polyene fatty acids. Under clinorotation, a percent of the cholesterol in the raft fraction has been increased 7 times in comparison with control.
            For the first time, the essential increase in the content of cholesterol and some saturated fatty acids in lipid rafts under clinorotation has been shown. This may indicate a raft rigidity strengthening under simulated microgravity that can lead to changes in plasmalemma permeability, selectivity and activity of corresponding proteins.   A higher raft rigidity occurs against the backdrop of maintaining microviscosity of the membrane itself at the normal level. It is proposed to emphasize attention on the research of the role of lipid rafts in plant cell gravisensitivity.
Keywords: clinorotation, fatty acids, Pisum sativum, plasmalemma, rafts, sterols
 1. Kordyum T. L., Nedukha, O. M. Grakhov, V. P., Mel’nik A. K., Vorobyova T. M., Klimenko O. M., Zhupanov I. V.[Study of the influence of simulated microgravity on the cytoplasmic membrane lipid bilayer of plant cells. Space Science and Technology, 21 ( 3), 40—47 (2015) [in Ukranian].
2. Polulyakh Yu. A. [Phospholipid and fatty acid content in the plasma membrane of pea root cells under clinorotation. Reports of the Academy of Sciences of the USSR, Section Biol., 10, 67—69 (1988).
3. Bhat R. A., Panstruga R. Lipid rafts in plants. Planta, 223, 5—1 (2005).
4. Bligh E. Y., Dyer W. J. A rapid method of total lipid extraction and purification. Can. J. Biochem. Physiol., 37, 911—917 (1959).
5. Borner G. H. H., Sherrier D. J., Weimar T., Michaelson L. V., Hawkins N. D., Macaskill A., et al. Analysis of detergent-resistant membranes in Arabidopsis. Evidence for plasma membrane lipid rafts. Plant Physiol., 137, 104—116 (2005).
6. Brown D. A., London E. Functions of lipid rafts in biological membranes. Annu. Rev. Cell Dev. Biol., 14, 111— 136 (1998).
7. Cacas J.-L., Furt F., Le Gu dard M., Schmitter J.M., Buré C., Gerbeau-Pissot P. Lipids of plant membrane rafts. Progress in Lipid Research, 51, 272—299 (2012).
8. Carde J.-P. Electron microscopy of plant cell membranes. Methods Enzymol. L. Packer R. Douce (Ed.). — USA: Academic Press Inc., 148, 599—622 (1987).
9. Demir F., Horntrich C., Blachutzik J. O., Scherzer S., Reinders Y., Kierszniowska S., et al. Arabidopsis nanodomain-delimited ABA signaling pathway regulates the anion channel SLAH3. Proc. Natl. Acad. Sci. USA, 110 (20), 8296—8301 (2013).
10. Edidin M. Lipids on the frontier: a century of cell-membrane bilayers. Nat. Rev. Mol. Cell Biol., 4, 414—418 (2003).
11. Engelman D. M. Membranes are more mosaic than fluid. Nature, 438, 578—580 (2005).
12. Ferl E. J., Wheeler R. M., Levine H. G., Paul A. L. Plants in space. Curr. Opin. Plant Biol., 5, 259—263 (2002).
13. Fujiwara M., Hamada S., Hiratsuka M., Fukao Y., Kawasaki T., Shimamoto K. Proteome analysis of detergentresistant membranes (DRMs) associated with OsRac1- mediated innate immunity in rice. Plant Cell Physiol., 50, 1191—1200 (2009).
14. Furt F., Lefebvre B., Cullimore J., Bessoule J.-J., Mongrand S. Plant lipid rafts. Plant Signal Behav., 2 (6), 508— 511 (2007).
15. Goldermann M., Hanke W. Ion channel are sensitive to gravity changes. Microgravity Sci. Technol., 13, 35—38 (2001).
16. Grennan A. K. Lipid rafts in plants. Plant Physiol., 143 (3), 1083—1085 (2007).
17. Gutierrez-Carbonell E., Takahashi D., Lüthje S., González-Reyes J. A., Mongrand S., Contreras-Moreira B., et al. Shotgun proteomic approach reveals that Fe deficiency causes marked changes in the protein profiles of plasma membrane and detergent-resistant microdomain preparations from Beta vulgaris roots. J. Proteome Res., 15 (8), 2510—2524 (2016).
18. Iswanto A. B., Kim J. Y. Lipid raft, regulator of plasmodesmal callose homeostasis. Plants (Basel), 6 (2), 15. (2017).
19. Kittang A. I., Iversen T. H., Fossum K. R., Mazars C., Carnero-Diaz E., Boucheron-Dubuisson E., et al. Exploration of plant growth and development using the European Modular cultivation System facility on the International Space Station. J. Plant Biology, 16 (3), 528—538 (2014).
20. Kordyum E. L. Biology of plant cells in microgravity and under clinostating. Int. Rev. Cytol., 171, 1—78 (1997).
21. Kordyum E. L. Plant cell gravisensitivity and adaptation to microgravity. J. Plant Biology, 16 (Suppl. 1), 79—90 (2014).
22. Kraft M. L. Plasma membrane organization and function: moving past lipid rafts. Mol. Biol. Cell., 24 (18), 2765— 2768 (2013).
23. Larsson Ch., Sommarin M., Widell S. Isolated of highly purified plant plasma membranes and separation of inside-out and right-side-out vesicles. Methods in Enzymology, 228, 451—469 (1994).
24. Lefebvre B., Furt F., Hartmann M.-A., Michaelson L. V., Carde J.-P., Sargueil-Boiron, F., et al. Characterization of lipid fafts from Medicago truncatula root plasma membranes: a proteomic study reveals the presence of a raft-associated redox system. Plant Physiol., 144 (1), 402—418 (2007).
25. Lingwood D., Simons K. Lipid rafts as a membrane-organizing principle. Science, 327 (5961), 46—50 (2010).
26. Mongrand S., Morel J., Laroche J., Claverol S., Carde J. P., Hartmann M. A., et al. Lipid rafts in higher plant cells: purification and characterization of Triton X-100- insoluble microdomains from tobacco plasma membrane. J. Biol. Chem., 279, 36277—36286 (2004).
27. Mongrand S., Stanislas T., Bayer E. M., Lherminier J., Simon-Plas F. Membrane rafts in plant cells. Trends Plant Sci., 15 (12), 656—663 (2010).
28. Morel J., Claverol S., Mongrand S., Furt F., Fromentin J., Bessoule J.-J., et al. Proteomics of plant detergent-resistant membranes. Mol. Cell. Proteomics, 5, 1396—1411 (2006).
29. Paul A. L., Zupanska A. K., Schultz E., Ferl R. J. Organspecific remodeling of the Arabidopsis transcriptome in response to spaceflight BMC. Plant Biol., 13, 112—122 (2013).
30. Peskan T., Westermann M., Oelmuller R. Identification of low-density Triton X-100-insoluble plasma membrane microdomains in higher plants. Eur. J. Biochem., 267, 6989—6995 (2000).
31. Seifert G. J., Xue H., Acet T. The Arabidopsis thaliana fasciclin like arabinogalactan protein 4 gene acts synergistically with abscisic acid signalling to control root growth. Ann. Bot., 114 (6), 1125—1133 (2014).
32. Sieber M., Hanke W., Kohn F. P. M. Modification of membrane fluidity by gravity. Open J. Biophysics, 4, 105— 111 (2014).
33. Simons K., Ikonen E. Functional rafts in cell membranes. Nature, 387, 569—572 (1997).
34. Sprenger R. R., Jensen, O. N. Proteomics and the dynamic plasma membrane: quo vadis? Proteomics, 10, 3997—4011 (2010).
35. Srivastava V., Malm E., Sundqvist G., Bulone V. Quantitative proteomics reveals that plasma membrane microdomains from poplar cell suspension cultures are enriched in markers of signal transduction, molecular transport, and callose biosynthesis. Mol. Cell Proteomics, 12 (12), 3874—3885 (2013).
36. Takahashi D., Kawamura Y., Yamashita T., Uemura M. Detergent-resistant plasma membrane proteome in oat and rye: similarities and dissimilarities between two monocotyledonous plants. J. Proteome Res., 11 (3), 1654—1665 (2012).
37. Wheeler R. M.Plants for human life support in space: from Myers to Mars. Gravit. Space Biol., 23, 25—35 (2010).