Change of fatty-acid composition in plants during adaptation to hypothermia

The study of inter-species variability of fatty acid composition in leaf tissues of three species of medicinal plants growing in Predbaikal’ye showed that this composition has a species-specific character. In the composition of unsaturated fatty acids of all the species studied there prevail poly-unsaturated fatty acids – linoleic and linolenic, which implies high values of double bonds values (up to 2,19 in the yarrow). Along with high values of desaturatioin ratio (up to 4.7 in yarrow), this fact proves high potential of cold resistance in the species under study. The analysis of seasonal changes in the fatty acid composition of the three species of medicinal plants demonstrated that with the average daily temperature going down, regular reduction in the content of saturated fatty acids and increase in the content of unsaturated fatty acids take place. Changes in fatty acid composition of lipids and the level of ω9- and ω3-desaturases activity in leaf tissues in the course of adaptation to reduction of average daily air temperature in the plants under study were found to have inter-species differences as well. The data acquired allow to presume that high cold resistance potential in the species under study is, among other things, linked to the processes of fatty acids biosynthesis within lipids.