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

Changes of Respiration Activities in Cells of Winter Wheat and Sugar Cane Suspension Cultures During Programmed Cell Death Process

Process of cell death in suspension cultures of winter wheat and sugar cane under high (50 °С) and negative (-8 °С) temperature treatment has been studied. It has been shown, that programmed cell death (PCD) process caused by the negative temperature in the culture of winter wheat was noted for slow rate of realization and it was carried out for 10 days. It has been state that rate of cell respiration was significantly higher than in the control culture. At the same time PCD processes induced by the high temperature in the culture of sugar cane and winter wheat and by the negative temperature in the culture of sugar cane realized for 24-48 h and was accompanied by graduate decrease of respiration activities. We can conclude that the main reason of PCD processes realization differences was a different level of respiration metabolism resistance to high and negative temperatures action

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

Activation of Cell Death in the Sugar Cane Suspension Culture by the Exposure to High Temperature

The process of cell death in a sugar cane suspension culture after exposure to high temperature (45, 50, 55 and 60 °C) during 10 min has been studied. It has been revealed that treatment of cell culture at 50 °C did not cause an immediate cell death, but 50% of the cells were dying for the next 48 h. Exposure of cell culture to more high temperature (55 - 60 °C) caused a massive cell death occurred instantly after treatment. The development of cell death after the treatment at 50 °C was accompanied by the protoplast condensation, increased generation of reactive oxygen species and hyperpolarization of the mitochondrial inner membrane. Obtained results indicate on the active character of the cell death process, induced by the moderate heat shock in sugar cane suspension culture

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

Tebuconazole Regulates Fatty Acid Composition of Etiolated Winter Wheat Seedlings

The fatty acid composition of shoots of unhardened and hardened to cold etiolated winter wheat seedlings grown from seeds treated with tebuconazole-based protectant «Bunker» (content of tebuconazole 60 grams per liter, g/L), and the seedlings frost resistance has been studied. It is shown that treatment of winter wheat seeds by «Bunker» preparation (1,5 microliter per gram of seeds, µl/g) is accompanied by an increase of the fatty acids unsaturation in the shoots and increase of the seedlings frost resistance (–8°C, 24 h). The most pronounced decrease in the content of saturated palmitic acid and increase in the content of unsaturated α-linolenic acid were observed during cold hardening of winter wheat seedlings grown from seeds treated by tebuconazole-based protectant. It is concluded that the seeds treatment with tebuconazole-based protectant causes changes of fatty acid composition of winter wheat seedlings to increase their frost resistance

Temperature Stress and Consequences of its Influence on Functional Activity of Mitochondria in Maize Etiolated Seedlings

Treatments of 30-min influences of high (32, 37, 42, 47, 52 °С) and low (0, 17, 22 °С) temperatures on viability of shoots, common activity of peroxidase, content of reactive oxygen species (ROS), intactness and oxidative activity of mitochondria from etiolated maize seedlings have been studied. It has been shown that 17, 32, 37 и 42 °С temperatures cause intensification of peroxidase activity, and 52 °С depresses this enzyme activity and then led to total death of shoots. ROS content in mitochondria increased during the treatment of seedlings with 0, 17, 22, 37 и 42 °С temperatures. All temperature exposures led to decrease of succinate oxidation rates in mitochondria, at that 47 и 52 °С temperatures inhibited mitochondria respiration to an even greater degree. However, if after the action of the temperature 47 °C the phosphorylating activity was maintained in the mitochondria, after 52 °C it was absent and mitochondria had reduced intactness of outer mitochondria membrane. Low temperatures led to uncouple of oxidative phosphorylation and activating of cyanide-resistant respiration. Role of mitochondria in plant response on the temperature stress has been discussed