THE ENERGETIC FUNCTIONS OF PLANT MITOCHONDRIA UNDER STRESS

This article reviews the involvement of the mitochondrial systems, which maintain the balance of cell energy at different stress conditions. It is shown the functioning of the alternative oxidase, free fatty acids, uncoupling proteins, the rotenone-insensitive NAD(P)H dehydrogenases, the ADP/ATP-antiporter, the permeability transition pore and ATP-sensitive potassium channel (К+ATP). It is discussed data about physiological role of these systems in plant cell

The role of mitochondria in response of wild grass Elymus sibiricus L. seedlings to temperature stress, water deficiency and hydrogen peroxide exposure

The relationship between energetic parameters and content of stress proteins (alternative oxidase, uncoupling protein and HSP70) in wild grass Elymus sibiricus mitochondria during different stress exposure (cold hardening, cold shock, high-temperature stress, water deficiency and oxidative stress) has been studied. It has been shown that influence of mild stress factors (cold hardening and exogenous 0.5 mM hydrogen peroxide treatment) result in adaptive changes related to the increase of activity alternative oxidase and the increase of content such proteins as alternative oxidase, uncoupling protein and HSP70. The comparative analysis of the function of the cultured and wild plants mitochondria in stress conditions has been produced

Role of Changes in Cell Fatty Acids Composition in the Increasing of Frost Resistance of Winter Wheat Suspension Culture

Influences of low temperatures (4 and 8 ° С) on the frost tolerance and fatty acid compositions of cells in a winter wheat suspension culture have been studied. It has been found that treatment of the culture with 4 °C (7 days) did not protect cells from subsequent freezing temperature action (-8 °С, 6 h) and was not accompanied significant changes in the fatty acid composition. On the contrary, the treatment of the culture with the temperature 8 °C (7 days) prevented the death caused by freezing temperature and the content of saturated fatty acids decreased: pentadecanoic acid (by 35,0%), palmitic acid (by 19,9%) and stearic acid (by 65,4%), and the content of α-linolenic acid increased by 94%. That was the cause of the double bond index (DBI) increase by 16%. The role of fatty acids composition changes in the process of increasing frost tolerance in plants are discussed

THE IMPORTANCE OF OXIDATIVE PHOSPHORYLATION UNCOUPLING SYSTEMS FUNCTION FOR SURVIVING OF WINTER WHEAT SEEDLING SHOOTS DURING SHORT-TERM COLD STRESS

The influence of uncoupling of oxidative phosphorylation in mitochondria on surviving of winter wheat seedling during low-temperature stress was investigated. It was shown that infiltration of winter wheat seedling by exogenous uncouplers caused the increase of oxygen consumption, seedling’s temperature and surviving. Vice verse inhibition of electron transport through the main cytochrome and alternative pathways decreased surviving of winter wheat seedlings during cold stres

Resistance of Winter Wheat Seedlings to Short-term Freezing Temperature Influence May be Determined by Activation of Uncoupling Protein and ATP/ADP Antiporter

Aftereffect of freezing temperature (-8 ° C, 1-6 h) on the content of reactive oxygen species (ROS), intactness mitochondria, their oxidative and phosphorylating activity and the contribution of uncoupling proteins (UCPs) and ATP/ADP antiporter to linoleate-induced mitochondrial respiration in winter wheat seedlings have been studied. It has been shown that the survival of seedlings during cold exposure is dependent on the activity of pUCP and ATP/ADP antiporter in mitochondria, the function of which under cold stress is probably the regulation of ROS content

The Tebuconazole-based Protectant of Seeds “Bunker” Induces the Synthesis of Dehydrins During Cold Hardening and Increases the Frost Resistance of Wheat Seedlings

Triazole derivatives are widely used in agriculture for seed protectant of cereals against seed and soil infection. Triazole derivatives can have an effect on the biochemical and physiological functions of plants. The tebuconazole-based protectant of seeds «Bunker» (content of tebuconazole 60 grams per liter, g/L) is a systemic fungicide of preventive and therapeutic action. The effect of the seed treatment by «Bunker» preparation on the shoot growth and cell viability coleoptile, synthesis of dehydrins in shoots and frost resistance etiolated winter and spring wheat seedlings has been studied. It has been shown that treatment of winter and spring wheat seed by «Bunker» preparation induces similar concentration-dependent inhibition of the coleoptiles length. At the recommended dose (0,5 liter per tonne of seeds, L/t) growth inhibition was 28 - 30%, at a concentration of 1 L/t – 33 - 36%, at a concentration of 1,5 L/t – 40 - 42%, at a concentration of 3 L/t – 43 - 47%, at a concentration of 4 L/t – 48 - 51% and at 5 L/t – 53 - 56%. The treatment of wheat seed by «Bunker» preparation had no phytotoxic effect on coleoptile cells in any of the studied concentrations, on the contrary, with increasing concentration of preparation observed the increase in cell viability, as measured by recovery of 2,3,5-triphenyltetrazolium chloride. We can assume that having retardant properties, tebuconazole not only inhibits the growth of plants, but also delays their aging. The treatment of seed protectant at a concentration of 1.5 L/t induced synthesis of the dehydrins with molecular masses about 19, 21, 22, 25 and 27 kD in winter wheat shoots and 18,6, 27 and 28,5 kD in spring wheat shoots during cold hardening. Among identified dehydrins the dehydrin of 27 kD is most significantly induced both in winter and spring wheat. The treatment of seed protectant «Bunker» in the same concentration increased the frost resistance of winter and spring wheat seedlings. It is supposed that increasing of cold and frost resistance of winter and spring wheat caused by seed treatment of the tebuconazole-based protectant may be associated with increase of the abscisic acid content – one of the triggers of the low-temperature adaptation of plants. It is concluded that tebuconazole-based protectant of seeds «Bunker» increases the resistance of wheat to low temperature, affecting the growth processes and the synthesis of stress proteins

The Relationships Among an Activity of the Alternative Pathway Respiratory Flux, a Content of Carbohydrates and a Frost-Resistance of Winter Wheat

A content of carbohydrates and dehydrins in the leaves, activities of the alternative (AP) and the cytochrome (CP) pathways of respiration in mitochondria, isolated from leaves, during cold hardening continuous light (5 °C) and dark conditions with sucrose (2 °C) and relationships among these parameters and a frost-resistance of winter wheat have been investigated. The direct relationship among the content of carbohydrates, the activity of AP and frost-resistance of winter wheat has been detected. It has been concluded that the activity of the alternative oxidase during cold hardening of winter wheat depends on the content of soluble carbohydrates and is necessary to maintain metabolic (red/ox) homeostasis in the cell at low temperatures

Comparative Analysis of Some Hsps Synthesis in Leaves of Transgenic Potato Plants with Gene gox at High Temperature

Analysis of control and transgenic plants of potato, grade Skarb, transformed by vector constructions pBI-L-GOX (LP line) и pBI-F-GOX (F line) with native gene of glucose oxidase gox and pBI-GOX-mod (MOD line) with modified gene gox-mod has been carried out. It has been shown that transgenic potato plants with genes gox and gox-mod did not have fenotypic differences with control plants. It has been confirmed that there was an increase of level of hydrogen peroxide produced by reaction, which catalized by glucose oxidase in leaves of transgenic plants. Using antibodies against some heat shock proteins (Hsp101, Hsp70/Hsc70, Hsp60, Hsp17.6C-1, Hsp17.6C-2) we revealed an increased content of Hsp17.6C-2 in leaves of LP line and Hsp60 in leaves of LP and F in the morning. It has been shown that rise in temperature in the daytime (from 18-23°С to 35-43°С) led to intensification of all studied Hsps synthesis both in control and in transformed lines

The Study of the Effects of Surface Dielectric Barrier Discharge Low Temperature Plasma Products on Spring and Winter Wheat Germination

The use of ion-plasma technologies for treatment of seeds of different crop plants is particularly important for regions that exist in environment of risk farming. This is due to the lack of supplies in the treatment, durability, reliability and performance of these technologies. However, the mixed results of studies obtained for different species and varieties of seeds, make it necessary to detail compare the effects of the low-temperature plasma products for different cultures. This paper presents the results of experimental studies of the effects of plasma products of surface dielectric barrier discharge on the germination of spring and winter wheat. It has been shown that irrespective of time and the exposure intensity laboratory germination of spring wheat seeds reduced of 74% in the control group to 52% of the treated seeds, while the germination of wheat seeds is not reduced even at a relatively long exposure (20 min). The modes of treatment (3 min, 2.1-2.4 kV) at which germination of winter wheat seeds increase from 81% in the control group to 87% of the treated seeds have been selected. Resistance of winter wheat seed germination to the product of the discharge plasma can be used to form the conditions for safe suppression of a variety of pathogenic organisms on the surface of seeds

COMPARISON OF STRESS PROTEINS PARTICIPATION IN ADAPTATION MECHANISMS OF BAIKALIAN AND PALEARCTIC AMPHIPOD (AMPHIPODA; CRUSTACEA) SPECIES

The aim of the present study was a study of the influence different stressful factor on syntheses and activity of the stress proteins (HSP70, sHSP and peroxidase) of freshwater organism. Six freshwater amphipod species were investigated: Eulimnogammarus cyaneus (Dyb.), E verrucosus (Gerstf.), E vittatus (Dyb.) - endemic species from Lake Baikal which were compared with Palearctic species - Gammarus lacustris Sars., G tigrinus (Sexton), Chaetogammarus ischnus (Stebbins). It was shown expression of sHSP by heat and toxic stresses for all amphipods species. Oxidative stress induced HSP70 for Palearctic species G tigrinus and C ischnus but not for baikalian species. Heat stress did not caused the increase of HSP70 level for Baikalian species of amphipods. The activity of the peroxidase was decrease by heat and toxic stresses. Oxidative stress caused the increase of peroxidase activity for Palearctic species, and the decrease for Baikalian once