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

Biological Effects of Potato Plants Transformation with Glucose Oxidase Gene and their Resistance to Hyperthermia

It is known that regulation of plant tolerance to adverse environmental factors is connected with short term increase of the concentration of endogenous reactive oxygen species (ROS), which are signalling molecules for the induction of protective mechanisms. Introduction and expression of heterologous gox gene, which encodes glucose oxidase enzyme in plant genome, induce constantly higher content of hydrogen peroxide in plant tissues. It is not known how the introduction of native or modified gox gene affects the plant resistance to high-temperature stress, one of the most commonly used model for the study of stress response and thermal tolerance. In this study, we investigated biological effects of transformation and evaluated the resistance to temperature stress of potato plants with altered levels of glucose oxidase expression. Transformation of potato plants by gox gene led to the more early coming out from tuber dormancy of transformed plants and slower growth rate. Transformants containing the glucose oxidase gene were more sensitive to lethal thermal shock (50 °C, 90 min) than the transformant with the empty vector (pBI) or untransformed plants (CK). Pre-heating of plants at 37 °C significantly weakened the damaging effect of lethal thermal shock. This attenuation was more significant in the non-transformed plants