Oats are one of the most useful and widespread cereal crops in the world. In permafrost conditions (Central Yakutia), based on metabolic changes in late summer-sown oat plants (Avena sativa L.), the key processes involved in the cold acclimation of a valuable cereal species were identified. During the onset of low ambient temperatures, metabolites from leaf samples were profiled using gas chromatography with mass spectrometry (GC-MS) and were analyzed using principal component analysis (PCA). A total of 41 metabolites were identified in oat leaves. It was found that acclimation to suboptimal temperatures during the fall period leads to biochemical (accumulation of mono- and disaccharides and decrease in fatty acids and polyols) as well as physiological and biophysical changes (decrease in leaf PRI reflectance indices and chlorophyll a fluorescence). Therefore, the study contributes to a more holistic understanding of oat metabolism under low-temperature cryolithozone stress. It is believed that the analysis of changes in leaf reflection properties and JIP-test parameters of chlorophyll a fluorescence using leaf metabolomic profiling can be used in the selection of valuable varieties of cereal crops to obtain plant fodders with high nutrient contents under conditions of a sharply continental climate.

The prevalence of coniferous trees in the forest landscapes of northeastern Siberia is conditioned by their high frost resistance. The Kajander larch (Larix cajanderi Mayr), which can survive under natural conditions (down to −60 °C) in the cryolithozone of Yakutia, is the dominant forest-forming species. We hypothesise that our study using HPTLC–UV/Vis/FLD, TLC–GC/FID, and GC–MS methods of seasonal features of the lipid profile of Kajander larch tissues will bring us closer to understanding the mechanisms of participation of lipid components in the adaptation of this valuable tree species to the cold climate of the cryolithozone. Rare delta5-unsaturated polymethylene-interrupted fatty acids (∆5-UPIFA) were identified in the fatty acids (FAs) of L. cajanderi shoots, including 18:2(Δ5.9) (taxoleic), 18:3(Δ5.9.12) (pinolenic), and 18:4(Δ5.9.12.15) (coniferonic). It was found that the content of ∆5-UPIFA in L. cajanderi shoots markedly increased (1.5-fold, representing up to 23.9% of sum FAs) during the autumnal transition of trees to dormancy. It was observed that the ranges of low temperatures experienced during the prolonged winter period primarily determined the structural diversity of membrane lipids and their constituent FAs during the cold adaptation of L. cajanderi. The results obtained can be used for the selection of molecular markers of cold tolerance in woody plants, including fruit trees.

Plant sterols (STs) are essential for the regulation of fluidity and permeability of cell membranes, which have a wide structural diversity. The dynamics of changes in sterol molecular species in leaves of a valuable cereal crop, spring oat (Avena sativa L.), as a function of different sowing dates were studied. In particular, 11 molecular species of sterols (STs) and triterpenoids in A. sativa leaves were identified by GC-MS. Triterpenoids Ψ-taraxasterol, cyclolaudenol, and betulin were identified in A. sativa leaves for the first time, which may be related to adaptation to extreme climatic conditions of the cryolithozone. The dynamics of STs and triterpenoids changes were revealed during growth and development of the standard term and late summer sowing term during A. sativa hardening to low ambient temperatures. The ratio of β-sitosterol to campesterol was found to increase in response to low positive air temperatures, while the ratio of stigmasterol to β-sitosterol remained constant from mid-September to the end of October. Overall, leaves of standard-seeded A. sativa plants maintained higher levels of absolute STs and triterpenoids by 1.9-fold than leaves of late-seeded A. sativa plants. It is suggested that the ability of A. sativa plants to synthesize β-sitosterol and stigmasterol may be part of an evolutionary adaptation process to cope with wide temperature fluctuations and to maintain important membrane-bound metabolic processes.

The seasonal patterns of changes in the content of lipophilic antioxidants β-carotene (β-Car), zeaxanthin (Zx), α-tocopherol (α-Toc), plastoquinone (PQ)/plastoquinol (PQH2) were studied in the assimilating shoots of evergreen shrub Ephedra monosperma J.G. Gmel ex C.A. Mey under natural conditions of Central Yakutia. The shortening of the photoperiod and the seasonal decrease in temperature induced a 1.4-fold increase in α-Toc content. The fall in the average daily temperature from 0.1 to -8.1°C in October led to a decrease in the content of β-Car as a result of the accumulation of rhodoxanthin (Rhd). In this period a sharp increase in the content of Zx retained overnight was also detected. In winter, elevated content of Zx and α-Toc persisted. During September, the content of PQH2 increased by 2.5 times and PQ by 1.4 times (compared to July). The beginning of exposure to freezing average daily temperatures from -3 to -5°C led to the depletion of the total PQ pool by 18%. However, the content of PQtot in the winter months was 1.5 times higher than at the end of July. The results revealed different timing and temperature ranges of variation for individual antioxidants during the development of frost resistance in ephedra.

Evergreen plants in permafrost ecosystems survive unfavorable autumn cooling and extremely low winter temperatures by maintaining optimal physiological activity of tissue cell membranes. To some extent, these features are due to the properties of shoot lipids performing a number of functions during adaptation. Sterols (STs) play a key role in regulating the fluidity and permeability of plant membranes (phytosterols) with a wide structural diversity. The composition of neutral lipids, STs, and fatty acids (FAs) in shoots of the evergreen shrub Ephedra monosperma growing in the Botanical Garden cryolithozone was first studied with HPTLC-UV/Vis/FLD and GC-MS. Twenty FAs were found, from C14:0 to C23:0; they included mono-, di-, tri-, and tetraene FAs. The high content of β-sitosterol among other ∆-5 sterols and an increased amount of C18:2(∆9,12) linoleic acid in lipids composition during the autumn–winter period was found to play an important role in the adaptation of ephedra shoots to the autumn–winter period, providing the cell membrane with greater plasticity, fluidity, and flexibility. The important role of diene linoleic fatty acid C18:2(∆9,12) in ephedra shoot lipids in the processes of low-temperature adaptation was shown.

Lipids are the fundamental components of cell membranes and they play a significant role in their integrity and fluidity. The alteration in lipid composition of membranes has been reported to be a major response to abiotic environmental stresses. Seasonal dynamics of membrane lipids in the shoots of Ephedra monosperma J.G. Gmel. ex C.A. Mey. growing in natural conditions of permafrost ecosystems was studied using HPTLC, GC-MS and ESI-MS. An important role of lipid metabolism was established during the autumn-winter period when the shoots of the evergreen shrub were exposed to low positive (3.6 °C), negative (−8.3 °C) and extremely low temperatures (−38.4 °C). Maximum accumulation of phosphatidic acid (PA), the amount of which is times times greater than the sum of phosphatidylcholine and phosphatidylethanolamine (PC + PE) was noted in shoots of E. monosperma in the summer-autumn period. The autumn hardening period (3.6 °C) is accompanied by active biosynthesis and accumulation of membrane lipids, a decrease of saturated 34:1 PCs, 34:1 PEs and 34:1 PAs, and an increase in unsaturated long-chain 38:5 PEs, 38:6 PEs, indicating that the adaptation of E. monosperma occurs not at the level of lipid classes but at the level of molecular species. At a further decrease of average daily air temperature in October (−8.3 °C) a sharp decline of PA level was registered. At an extreme reduction of environmental temperature (−38.4 °C) the content of non-bilayer PE and PA increases, the level of unsaturated fatty acids (FA) rises due to the increase of C18:2(Δ9,12) and C18:3(Δ9,12,15) acids and the decrease of C16:0 acids. It is concluded that changes in lipid metabolism reflect structural and functional reorganization of cell membranes and are an integral component of the complex process of plant hardening to low temperatures, which contributes to the survival of E. monosperma monocotyledonous plants in the extreme conditions of the Yakutia cryolithozone.

Mowing the plant shoots under hot, sunny, and dry conditions severely traumatizes the entire vegetative body, and the overall life cycle of the plant is altered. The purpose of the present research was to investigate the effects of mowing and drying on lipids, fatty acids (FA), sterols, and the systemic responses in leaves of plant material at three time points (24 h, 72 h, and leaves of new shoots after traumatic mowing in summer (1 July) and those subjected to cold hardening by autumn temperatures in September (aftergrass)) were analyzed for the first time. The leaves of five species of herbaceous plants growing in permafrost ecosystems were analyzed by HPTLC and GC-MS. It was established that fatty acids in the tissues of aftergrass leaves were characterized by higher values of the n-6/n-3 ratio than in summer grasses. It was demonstrated that exposure of leaves for 72 h in natural conditions in summer and at low temperatures in autumn in leaves of aftergrass resulted in significant changes in the composition of membrane phospholipids. The obtained findings indicate that leaves of aftergrass are the most valuable plant raw material in terms of FAs and phytosterols content compared to hay mowed in summer.

The Yakutian cattle is an indigenous Siberian cattle breed living in an extremely cold climate in some parts of Yakutia. There are only a few thousand animals of this breed, and the conservation of the Yakutian cattle is embedded in the international agenda. We studied the fatty acid profiles in the meat, liver, and fat of the Yakutian cattle (five individuals) of different ages and their main food resource–pasture plants. The fatty acid profile of the tissues of the Yakutian cattle differed from that of pasture plants: 16:0, 18:2n–6, and 18:3n–3 dominated in the pasture plants; 16:0, 18:0, 18:1n–9, 18:2n–6, 20:4n–6, 20:5n–3, and 22:5n–3 dominated in the meat and liver; and 16:0, 18:0, and 18:1n–9 dominated in the fat. The fatty acid composition of food products is related to the risk of developing cardiovascular disease (CVD). The meat and liver of the Yakutian cattle are health food products that contribute to decreasing the risk of developing CVD because of their rather high content of eicosapentaenoic and docosahexaenoic fatty acids, optimal n–6/n–3 and polyunsaturated fatty acids/saturated fatty acids ratios, low values of indexes of atherogenicity and thrombogenicity, and high values of hypocholesterolemic/hypercholesterolemic and health-promoting indexes. The results of the present study support the importance of preserving this valuable cattle breed. Actions should be taken to increase their population while retaining their contemporary housing and feeding conditions.

The composition of fatty acids in the general lipid balance of Dracocephalum palmatum Steph. Ex Willd that is found in extreme climatic conditions (Northern Pole of Cold) was researched by thinlayer and gas-liquid chromatography. This research aims to study the fatty acid profile of the perennial species Dracocephalum palmatum used as a medicinal herb in traditional medicine. We established that polyunsaturated fatty acids [FA], and more specifically linoleic and alpha-Linoleic acids, are prevalent in the lipidic constitution. The exceptional resilience of arctic and boreal plants is attributed to their flexible energy system that includes carbohydrates, proteins, and lipids. The latter are crucial in the energy balance of plants because they function as the main accumulator of spare energy and can create optimal conditions in cell membranes, unlike carbohydrates and proteins. Polyunsaturated fatty acids [PFA] present in the lipid layer allow the membranes to stay in the liquid state. Fat oxidation releases an amount of water that is considerably greater than that released by the combustion of carbohydrates and proteins. This research reveals that the fluidity of membranes in the arctic plant in question is optimal due to a high level of unsaturated lipids. The high amount of unsaturated FA in Dracocephalum palmatum lipids is attributed to the plant adapting to its poor growing conditions. We assume that late flowering plants with a higher than average level of PFA (linoleic and linolenic acids) higher than average play an important role in the conservation of reaction energy resources of animals in the northern environment.

Yakutia is a zone of continuous permafrost distribution, and its uniqueness lies in the fact that it has a kind of hidden biological resource that allows herbivores to survive even in conditions of limited floristic diversity. The current paper focuses on the disclosure of this resource, which we believe is in the nutritional value of permafrost plants. We have studied the content of total lipids and their essential polyunsaturated fatty acids in summer and autumn vegetative plants. According to the goal stated, we have pioneered the use of thin-layer and gas-liquid chromatography and mass spectrometry to show seasonal changes in the content of total lipids and their essential polyunsaturated fatty acids in the following plants: annual Avena sativa L. of standard and late sowing dates, and perennial Bromopsis inermis Leys before and after summer mowing in the conditions of Central Yakutia. Artificial shortening of the vegetation period of grasses has led to their preservation by natural cold (green cryo-feed). We have found that an increase in the amount of lipids in cereal plants occurs with the onset of low hardening air temperatures in the autumn period, in particular, a significant increase in linoleic С18:2(ω-6) and α-linolenic С18:3(ω-3) acids compared with indicators of summer vegetative plants. The detected process may indicate an increase in the energy intensity of frozen feed, thereby determining the important role of cryo-feed for pre-winter fat accumulation in herbivores in the cryolithozone. In the body of animals, soluble sugars of autumn vegetative or winter-green plants growing or frozen by natural cold and used as autumn and winter feed are converted into medium- and long-chain essential polyunsaturated fatty acids of the omega-6 and omega-3 families (arachidonic, and eicosapentaenoic and docosahexaenoic acids, respectively) and to a large extent help to winter. The use of grown green cryo-feed as a vitamin supplement for farm animals during a long stall period will open up new opportunities in increasing the productivity of livestock breeding in Yakutia in the future and help optimize the flow of substances and energy along the trophic cryo-feed – animal – human chain. Essential PUFAs, namely linoleic and α-linolenic acids, play an essential role in health and prolonging human life.

Наибольшую кормовую ценность имеют северные луговые фитоценозы, которые в первой половине лета подвергаются длительному заливанию паводковыми водами, стравливанию животными и хозяйственному скашиванию. Поэтому у многих травянистых растений наблюдается два цикла роста. Первый цикл приходится на начало вегетации растений до затопления их паводковыми водами или механического повреждения, обычно он длится до середины лета. Northern meadow phytocenoses have the greatest food value, which in the first half of summer are subjected to prolonged flooding with flood waters, grazing by animals and economic mowing. Therefore, many herbaceous plants have two growth cycles. The first cycle occurs at the beginning of the growing season of plants before they are flooded by flood waters or mechanically damaged; it usually lasts until mid-summer.

The lipid composition of two species of vascular plants, Equisetum variegatum Schleich. ex. Web. and E. scirpoides Michx., growing in the permafrost zone (Northeastern Yakutia, the Pole of Cold of the Northern Hemisphere), with average daily air temperatures in summer of +17.8 °C, in autumn of +0.6 °C, and in winter of −46.7 °C, was comparatively studied. The most significant seasonal trend of lipid composition was an accumulation of PA in both horsetail species in the autumn–winter period. Cold acclimation in autumn was accompanied by a decrease in the proportion of bilayer-forming lipids (phosphatidylcholine in the non-photosynthetic membranes and MGDG in photosynthetic membranes), an increase in the desaturation degree due to the accumulation of triene fatty acids (E. scirpoides), and an accumulation of betaine lipids O-(1,2-diacylglycero)-N,N,N-trimethylhomoserine (DGTS). The inverse changes in some parameters were registered in the winter period, including an increase in the proportion of “bilayer” lipids and decrease in the unsaturation degree. According to the data obtained, it can be concluded that high levels of accumulation of membrane lipids and polyunsaturated FAs (PUFAs), as well as the presence of Δ5 FAs in lipids, are apparently features of cold hardening of perennial herbaceous plants in the cryolithozone.

Аннотация. Целью данного исследования явилось сравнительное исследование фотосинтетических пигментов кормовых растений, произрастающих в Центральной Якутии. С помощью физико-химических методов (тонкослойной хроматографии, спектрофотометрии) выделены и определены состав и содержание фотосинтетических пигментов (хлорофиллы a и b, каротиноидов) из зеленых листьев некоторых кормовых растений. Установлено, что содержание желтых пигментов-каротиноидов было высоким у тех кормовых трав, у которых было обнаружено высокое абсолютное содержание (мг/г) зеленых пигментов. Выявлено, что криокорм (криокорм – консервированная невозвратным естественным холодом криолитозоны Севера зеленая масса, посевных холодоустойчивых кормовых растений) из Avena sativa L. (овса посевного) имеетнаиболее высокую кормовую ценность по отношению к фотосинтетическим пигментам(1,5–2 раза), чем растения, произрастающие в естественных природных условиях. По нашемумнению, ключевую роль в жизнедеятельности животных в условиях экстремальных низких температур окружающей среды играют богатые энергией биологически активные вещества(лютеин и β-каротин) кормовых растений Якутии, синтезируемые в осенний период в ходехолодового закаливания. Кроме того, лютеин является одним из физиологически активныхвеществ, входящих в состав коровьего молока.

It is known that phytosterols have high immunomodulating, hypocholesterolemic and oncoprotective activity and are widely used in medicine. In addition, the plants containing them are used in feed of farm animals as dietary supplements that stimulate growth and the immune system. Promising, but poorly studied, sources of these biologically active compounds may be plants of the class Horsetails (Equisetopsida), grown under extreme conditions of sharply continental climate of Yakutia. The steric composition of the aerial part of the variegated horsetail (Equisétum variegatum) was studied for the first time during the summer and autumn vegetation. It is shown that the composition of the main free sterols includes β-sitosterol, campesterol, stigmasterol, isofucosterol, as well as a small amount of cholesterol. The total amount of free and bound sterols in the tissues of the aerial part of this species is about 0.5 mg/g dry weight or 2% of the total content of all lipid components. Moreover, the content of free sterols in the aerial part of variegated horsetail is an order of magnitude higher than the content of sterol esters in these tissues. Peculiarities of the seasonal (autumn-summer) dynamics of changes in the relative contents of stigmasterol, campesterol and isofucosterol and the absolute total content of sterols in the aerial part of variegated horsetail are revealed.

Absolute and relative content and composition of fatty acids, total lipids, and phospholipids, as principal constituents of cell membranes, were examined on vegetative buds of deciduous trees and shrubs throughout the summer and autumn–winter seasons under climatic conditions of the cryolithozone of Yakutia. Lipid metabolism was found to play an essential role in plants' adaptation to low autumnal and winter temperatures in the permafrost zone of Yakutia. The content of phosphatidylcholine in leaf buds of the birch Betula pendula Roth and the shrub Alnus alnobetula subsp. fruticosa (Rupr.) Raus increased throughout the observation period from 9.9 to 23.4 mg/g dry wt. In the autumn–winter period, the composition of fatty acids in the bud lipids of both species was characterized by a high content of unsaturated C18:2 and C18:3 acids. Biosynthesis of fatty acids in buds of deciduous trees and shrubs at a low temperature was apparently controlled by ω3-desaturase, whose activity elevated the content of α-linolenic acid from 2.9 to 5.7 mg/g in B. pendula and from 1.6 to 4.8 mg/g dry wt in A. alnobetula subsp. fruticosa. The seasonal decrease in air temperature was accompanied by an increase in the unsaturation coefficient (k) from 0.9 to 2.3 in B. pendula and from 1.4 to 1.8 in A. alnobetula subsp. fruticosa. It is proposed that the high content of polyunsaturated fatty acids in the autumn–winter period in vegetative buds of the examined woody plants is determined by a complex of climatic factors of the permafrost zone, such as a sharply contrasting day and night temperatures during plant dormancy, extremely low air temperature in winter (down to –60°С), and a short daylight period at this time of the year.

: For the first time, seasonal changes in the content of total lipids (TLs) and phospholipids (PLs) were studied in fodder plants growing in Central Yakutia-a perennial cereal, smooth brome (Bromopsis inermis L.), and an annual cereal, common oat (Avena sativa L.). Both species have concentrated TLs and PLs in autumn under cold hardening. In addition, a significant increase in the content of fatty acids (FAs) of B. inermis was observed during the autumn decrease in temperature. The Yakutian horses, which fed on cereals enriched with nutrients preserved by natural cold (green cryo-fodder), accumulated significant amounts of 18:2n-6 and 18:3n-3, the total content of which in cereals was 75% of the total FA content. We found differences in the distribution of these two FAs in different tissues of the horses. Thus, liver was rich in 18:2n-6, while muscle and adipose tissues accumulated mainly 18:3n-3. Such a distribution may indicate different roles of these FAs in the metabolism of the horses. According to FA content, meat of the Yakutian horses is a valuable dietary product.

This article examines approaches to the problem of assessing and evaluating competences, methods and mechanisms for measuring results of the educational program 44.03.05 - "Pedagogical Education", the specialization "Biology and Chemistry" in a particular regional university environment. The study has established that competences play the main role as the final result of education in the real educational process within the competency based approach, while educational technologies serve for the formation of these competences. Evaluation tools, assessment technologies and evaluation procedures serve as a means of the claimed results proof. The application of the competency based approach in the educational process is closely connected with the problem of assessing students' competence. Competency and competence are able to act as the main systemforming factors, which unites the activity of various departments of the university or teaching modulars (subjects) within a particular educational institution. Our educational program of the educational program "Pedagogical Education", being a methodological system for applying the ideas of the competency based approach, is aimed at solving problems in the field of professional activity, since it is focused on the formation of the methodological student competence while being one of the approaches to assess and evaluate students' competences.