Vegetative plants in Yakutia are naturally frozen when they are covered with snow in the fall, and they function as green cryo-fodder that is a source of biologically active substances and nutrients for herbivorous animals. We observed a considerable increase in the total fatty acid content in the leaves of Avena sativa, Elytrigia rеpens, Equisetum variegatum and Equisetum scirpoides during the fall period. However, the degree of unsaturation of fatty acids was not higher in the frozen plants covered with snow than in the summer plants, with the exception of E. scirpoides, a dwarf horsetail found in the Pole of Cold in the northern hemisphere. In the internal adipose tissue of the Yakut horse (young horse meat), 18 fatty acids were found, including 10 saturated ones. Monounsaturated oleic С18:1 (n-9) acid and polyunsaturated α-linolenic С18:3 (n-3) acid were equally prevalent among the unsaturated fatty acids, accounting for 70% of the total unsaturated fatty acids. This composition of polyenoic fatty acids in the internal adipose tissue indicates that the Yakut horse actively feeds on the fall vegetation and the wintergreen sedge-grass. We believe that the high plant-specific free fatty acid content in the tissue of Yakut horses may play an important role in the regulation of their resistance to long-term low-temperature stress.Key words : Adaptation, cryoresistance, fatty acids, grass plant, Yakut horse *Corresponding authors *Tel : +82-51-510-2280, Fax : +82-51-513-9258 *E-mail : chlee@pusan.ac.kr (Choon-Hwan Lee) kap_75@bk.ru (Klim Alekseevich Petrov) This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
IntroductionIn the territory of Central and North-East Yakutia (the Siberian region), plants and animals face with the influence of virtually extreme cold conditions. Long-term winter frosts of high degree with temperature ranged from -40 up to -45℃ (with air temperature absolute minimum up to -68℃) and a small amount of snowpack caused by the arid harsh continental climate formed the eternal frost zone (cryolithic zone) here.Plant developed various adaptive and defensive mechanisms to survive under adverse growth conditions [7]. In such conditions, in particular during cold hardening the local plants acquired the ability to accumulate large amounts of various substances-proteins, carbohydrates, lipids (fatty oils), carotenoids, vitamins and many other products of secondary metabolism. This ability is largely used by people and animals for nutritional purposes and for the support of a considerable part of their energy demands; it serves a source of valuable fatty acids (FAs) as well.Since the time when the hypothesis about the role of membrane lipids in adaptation appeared [24,31], the extensive experimental evidences concerning the influence of external cond...
