Ca-dependent oxidation of exogenous NADH and NADPH by the mitochondria of spring wheat and its relation with AOX capacity and ROS content at high temperatures.

Mitochondria are sources of reactive oxygen species (ROS) in a plant cell under high temperature. Mitochondrial alternative NAD(P)H dehydrogenases (type II NAD(P)H DHs) and cyanide-resistant oxidase (AOX) can regulate ROS production, but their role at high temperatures is unknown. This study investigates the influence heat acclimation (37 °C) and heat shock (50 °C) temperatures on ROS content, activity and protein abundance of external Ca-dependent NAD(P)H DHs (NDB) and AOX in mitochondria of 4- and 8-day-old seedlings of spring wheat (Triticum aestivum L.

Mitochondrial alternative cyanide-resistant oxidase is involved in an increase of heat stress tolerance in spring wheat.

The aim of this study was to determine the influence of different heat treatments on the alternative cyanide-resistant oxidase (AOX) capacity and establish a relation between the heat stress tolerance of spring wheat (Triticum aestivum L.), content of water-soluble carbohydrates in leaves and the alternative respiratory pathway (AP) capacity. We identified a positive relation between these studied parameters.

Expression profiles of genes for mitochondrial respiratory energy-dissipating systems and antioxidant enzymes in wheat leaves during de-etiolation.

Mitochondrial respiratory components participate in the maintenance of chloroplast functional activity. This study investigates the effects 48h de-etiolation of spring wheat seedlings (Triticum aestivum L., var.

[Impossible mechanisms of germatranol influence on the thermal stability of wheat germs].

The influence of biologically active substance germatranol in low and very low doses on the respiration rate and the content of reactive oxygen species (ROS) in wheat roots under conditions of high stress was investigated. The results showed that solutions of the studied substance in concentrations of from 10–5 M to 10–10 M (depending on the temperature) increase the thermotolerance of wheat germs and affect the ROS content and respiration rate. It is assumed that germatranol can have a positive impact on plant growth and development and act as antioxidants in plant cells.

Light regulation of mitochondrial alternative oxidase pathway during greening of etiolated wheat seedlings.

This study deals with effects of de-etiolation (48h) of spring wheat (Triticum aestivum L., var. Irgina) seedlings on differential expression of AOX1 genes, levels of AOX protein and the alternative respiratory pathway (AP) capacity.

Mitochondrial energy-dissipating systems (alternative oxidase, uncoupling proteins, and external NADH dehydrogenase) are involved in development of frost-resistance of winter wheat seedlings.

Gene expression, protein synthesis, and activities of alternative oxidase (AOX), uncoupling proteins (UCP), adenine nucleotide translocator (ANT), and non-coupled NAD(P)H dehydrogenases (NDex, NDPex, and NDin) were studied in shoots of etiolated winter wheat (Triticum aestivum L.) seedlings after exposure to hardening low positive (2°C for 7 days) and freezing (-2°C for 2 days) temperatures. The cold hardening efficiently increased frost-resistance of the seedlings and decreased the generation of reactive oxygen species (ROS) during further cold shock.

Evaluation of biochemical responses in Palearctic and Lake Baikal endemic amphipod species exposed to CdCl2.

This study evaluated small heat shock proteins (sHSP) (related to alpha-crystallin) and antioxidant enzymes (POD, peroxidase and CAT, catalase) as possible biomarkers for use in toxicological studies. Biochemical responses to cadmium chloride in two Lake Baikal endemic amphipods (Eulimnogammarus verrucosus, Eulimnogammarus cyaneus) and Palearctic species (Gammarus lacustris) were compared. Our findings showed that cadmium chloride toxicity directly influenced POD activity and sHSP synthesis in all amphipod species.

Non-phosphorylating bypass of the plant mitochondrial respiratory chain by stress protein CSP 310.

Recently, it has been reported that the cold-stress protein CSP 310, discovered in the cytoplasm of cold-resistant winter cereals, causes uncoupling of oxidative phosphorylation during cold stress. To understand how the uncoupling mechanism of CSP differs from that of cyanide-insensitive alternative oxidase and plant mitochondrial uncoupling protein, we determined the effect of respiratory-chain inhibition on winter wheat (Triticum aestivum L. cv.

Influence of stress protein CSP 310 and antiserum against this protein on oxygen uptake, lipid peroxidation, and temperature of winter wheat seedling shoots during cold stress.

It is determined that infiltration of winter wheat seedling shoots by anti-CSP 310 antiserum caused a significant decrease of oxygen uptake in winter wheat shoots during short-term cold stress. On the other hand, infiltration of winter wheat seedling shoots by stress protein CSP 310 caused an increase of oxygen consumption. The comparison of the influence of infiltration of winter wheat shoots by CSP 310 and anti-CSP 310 antiserum on the rate of lipid peroxidation showed that, if infiltration by CSP 310 caused a decrease of conjugated diene formation, infiltration by anti-CSP 310 antiserum did not cause any significant changes in the rate of lipid peroxidation.

Stress-induced protein CSP 310: a third uncoupling system in plants.

Addition of the cold-stress-related protein CSP 310 to mitochondria isolated from winter wheat ( Triticum aestivum L. cv. Zalarinka), winter rye ( Secale cereale L.

Influence of CSP 310 and CSP 310-like proteins from cereals on mitochondrial energetic activity and lipid peroxidation in vitro and in vivo.

Background: The development of chilling and freezing injury symptoms in plants is known to frequently coincide with peroxidation of free fatty acids. Mitochondria are one of the major sources of reactive oxygen species during cold stress. Recently it has been suggested that uncoupling of oxidation and phosphorylation in mitochondria during oxidative stress can decrease ROS formation by mitochondrial respiratory chain generation.

Stress protein CSP 310 causes oxidation and phosphorylation uncoupling during low-temperature stress only in cereal but not in dycotyledon mitochondria.

It was found that an addition of antiserum obtained against stress protein 310 kD increased coupling of oxidation and phosphorylation in mitochondria isolated from cold-stress winter rye shoots and had no influence on dycotiledon mitochondria (pumpkins and sunflower). The data obtained showed a difference between molecular weights of dycotyledon polypeptides with immunochemical affinity to CSP 310 and CSP 310 subunits. It was shown that low-temperaturestress caused a transition to a low-energy state ("cold uncoupling") of free from endogenous free fatty acid cereal mitochondria.

An influence of antiserum against winter wheat stress uncoupling protein, CSP 310, on energetic activity of some plant species mitochondria.

It is determined that addition of an anti-CSP 310 antiserum to isolated mitochondria of cereals (winter rye, winter wheat, and maize) caused an increasing of mitochondrial respiratory control. In a similar manner, addition of this antiserum to isolated pea mitochondria did not cause this effect. It is shown that coupling effect of antiserum is not dependent upon the presence of bovine serum albumin in mitochondria incubation media.

An influence of stress protein CSP 310 and antiserum against this protein on lipid peroxidation in cereal mitochondria.

It is determined that an addition of an anti-CSP 310 antiserum to isolated winter wheat and maize mitochondria caused more significant increasing of spontaneous lipid peroxidation than the addition of stress protein CSP 310. It is shown that, at function of different mitochondrial respiratory chain complexes, the lipid peroxidation in winter wheat and maize mitochondria take place with different intensities. Under the functioning of mitochondrial respiratory chain complex IV, the maximum output of lipid peroxidation products, dienic conjugates is detected.

The search for proteins with immunochemical affinity to plant stress proteins at cold-adapted endemic Baikal fishes.

The search for proteins with immunochemical affinity to plant stress proteins in endemic Baikal fishes shows the presence of proteins, immunochemically related to plant heat-stabile proteins and plant uncoupling protein CSP 310. Western blotting showed that among the native cytoplasmic proteins of endemic Baikal fishes there are proteins immunochemically related to heat-stabile plant proteins with molecular weights about 480, 200-290, 150, 140 and about 90-100kD. SDS-electrophoresis showed the presence of polypeptides with molecular weights 23, 17 and 14kD in all species investigated and an additional 35kD polypeptide in Cottocomephorus grewingki.

The comparison of uncoupling activity of constituently synthesised and stress-induced forms of winter rye stress uncoupling protein CSP 310.

A difference between the uncoupling action of constituently synthesised and stress-induced forms of winter rye stress uncoupling protein CSP 310 on winter wheat mitochondria in vitro was found from the initiation of incubation. The uncoupling activity of CSP 310 depended on its concentration in the incubation media. The addition of anti-CSP 310 antiserum to isolated mitochondria from stressed winter rye shoots caused coupling of oxidation and phosphorylation.

Complex I of winter wheat mitochondria respiratory chain is the most sensitive to uncoupling action of plant stress-related uncoupling protein CSP 310.

The influence of stress uncoupling protein CSP 310 on functional stability of different mitochondrial respiratory chain complexes was analysed using various substrates of the tricarboxylic acid cycle. Complex I was the most sensitive to CSP 310 uncoupling action whilst other complexes were more stabile. It is proposed that the key point of CSP 310 uncoupling action is complex I of plant mitochondrial respiratory chain.

Plant stress-related uncoupling protein CSP 310 caused lipid peroxidation in winter wheat mitochondria under chilling stress.

The effect of CSP 310 on lipid peroxidation in winter wheat mitochondria was studied by the measurement of primary lipid peroxidation products - dienic conjugates. It was found that some concentrations of CSP 310 caused lipid peroxidation in isolated winter wheat mitochondria in all systems investigated at different concentrations during chilling stress.