Fatty acid profile and biochemical properties of Dracocephalum palmatum Steph. ex Willd in extreme climate 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

Exploring lipophilic antioxidants accumulation in field-grown low temperature-stressed Ephedra monosperma

The seasonal patterns of changes in the content of lipophilic antioxidants $\beta$-carotene ($\beta$-Car), zeaxanthin (Zx), $\alpha$-tocopherol ($\alpha$-Toc), plastoquinone (PQ)/plastoquinol ($PQH_{2}$) 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 $\alpha$-Toc content. The fall in the average daily temperature from 0.1 to $-8.1^{\circ}C$ in October led to a decrease in the content of $\beta$-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 $\alpha$-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 $-5^{\circ}C$ led to the depletion of the total PQ pool by 18%. However, the content of $PQ_{tot}$ 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

Study of the Effect of Mowing and Drying on the Lipid Composition of Grass Leaves in Permafrost Ecosystems

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 Composition and the Content of ∆-5 Sterols, Fatty Acids, and the Activity of Acyl-Lipid Desaturases in the Shoots of <i>Ephedra monosperma</i>, Introduced in the Botanical Garden of the Cryolithozone of Yakutia

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

Influence of Extremely Low Temperatures of the Pole of Cold on the Lipid and Fatty-Acid Composition of Aerial Parts of the Horsetail Family (Equisetaceae)

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

Fatty Acid Content and Composition of the Yakutian Horses and Their Main Food Source: Living in Extreme Winter Conditions

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&mdash;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

Role of Lipids of the Evergreen Shrub <i>Ephedra monosperma</i> in Adaptation to Low Temperature in the Cryolithozone

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