Specific and non-specific changes in plasmalemma lipid content induced by different types of abiotic stress

Effects of different abiotic stresses (hyperosmotic, hypoosmotic, and oxidative) on the lipid profile of the plasma membrane of table beet root cells (Beta vulgaris L.) were studied. Changes in the composition of membrane lipids under different types of stress had their distinctive features. The content of such lipids as phosphatidylethanolamines, phosphatidylglycerols, monogalactosyldiacylglycerides (MGDG), pentodecanoic fatty acid, cholesterol and stigmasterol, decreased under all types of stress, while the content of digalactosyldiacylglycerides (DGDG), arachic fatty acid and β-sitosterol and the DGDG/MGDG ratio increased under all types of stress. These effects of stress can be classified as nonspecific. However, for some lipids, stress-induced changes in their content depended on the type of stress. For example, the content of sphingolipids increased significantly under hyperosmotic stress and decreased under hypoosmotic and oxidative stress. In contrast, the content of sterols increased under hypoosmotic stress and decreased under hyperosmotic stress, and the content of sterol esters increased only under oxidative stress. Changes in the composition of these lipids can be regarded as specific. Changes in the content of phosphatidic acid, phosphatidylserines, phosphatidylinositols, phosphatidylcholines, and most fatty acids, as well as in ratio of phosphatidylcholines to phosphatidylethanolamines and some other parameters can also be attributed to specific. In conclusion, this study demonstrates that different types of abiotic stress induce different changes in membrane lipid content. These results may contribute to a better understanding of adaptation mechanisms and help in the development of new strategies to improve plant stress resistance.