A. A. Okanenko

Redistribution of elements of metals in plant tissues under treatment by non-ionic colloidal solution of biogenic metal nanoparticles

The content of metal elements in plant tissues of 10-day wheat seedlings after seed pre-treatment and foliar treatment with non-ionic colloidal solution of metal nanoparticles (Fe, Mn, Cu, Zn) was determined by an atomic absorption spectrometer. It was shown that metal nanoparticles due to their physical properties (nanoscale and uncharged state) were capable of penetrating rapidly into plant cells and optimizing plant metabolic processes at the early stages of growth and development.

Sulphoquinovosyldiacylglycerol and Adaptation Syndrome

The effect of drought factor induced the SQDG accumulation in leaves of drought resistant wheat plants and the drastic decrease of their content in sensitive plants. Heat and water stress combined induced SQDG accumulation in resistant plants, while it decreased in sensitive variety more drastically if compared with single factor effect. SQDG accumulation in wheat plants infected by Puccinia graminis and in kidney bean plants infected by tobacco mosaic and potato x viruses was observed as well. Lead stress changed drastically the glycolipid composition in laboratory experiments. Significantly lower SQDG content observed could be connected with possible competitive sulphur usage for sulphur containing polypeptide and protein synthesis judging by increasing protein content, or perhaps creating complexes with Pb. Thus we assume that SQDG could play special role in adaptation reactions connected mainly with stabilising the photosynthesis processes and perhaps heavy metal binding.

Virus impact upon bean plant photosynthesising tissue lipid composition

Study of bean plants infected by tabacco mosaic virus and potato X virus was performed. Virus infection of bean plants induced the injury of structural state of photosynthetic apparatus, viz., the a/b chlorophyll ratio decreased and the main photosynthetic membrane lipid monogalactosyl diacylglycerol degradation took place with parallel accumulation of intermediate compound suggested to perform a signal function. Phospholipid and free sterol content increase pointed out on the changes of the membrane fluidity and permeability. Accumulation of sulphoquinovosyl diacylglycerol in infected plants evidences the probability of latter to play important roles in adaptive reactions of photosynthetic apparatus.

Impact of Lead and Sulfur Deprivation on Soybean Plants

Lipid peroxidation products, antioxidative enzymes (superoxide dismutase and catalase) and water-soluble non-protein and water-soluble protein thiol contents were studied in soybean leaves affected by sulfate deprivation and Pb exposure. Sulfur promoted the regulation of adaptive reactions via an enhanced formation of water-soluble non-protein thiols. The reaction of soybean plants to Pb exposure was dependent on sulfur supply. At sufficient-sulfur conditions, higher water-soluble non-protein thiol compounds might contribute to better defense against Pb.

Glycolipid Fatty Acids While Drought Action

The results of soil water deficit action on the fatty acid glycolipid composition of different wheat variety chloroplasts (Triticum aestivum L.) are presented. It is shown that the decrease of glycolipid fatty acid unsaturation and activation of peroxidation processes in chloroplasts of sensitive plants grown under stress condition occur. The chloroplasts of drought resistant variety was characterised both by the accumulation of unsaturated fatty acid residues in digalactosyl diacylglycerol and by the absence of changes in sulphoquinovosyl diacylglycerol without increasing peroxidation. The role of transformations in the composition of chloroplast glycolipid fatty acids is discussed.

The Wheat Thylakoid Lipid Content Affected by Heat

Plants are impacted by unfavourable factors of the environment — drought, heat, frost etc. on the significant areas of different soil climatic regions of Europe. On solving the problem of physiological and biochemical mechanisms of plant acclimation and resistance, special emphasis is laid on the physical properties of photosynthetic membranes, their ability to provide the conditions needed for normal functioning enzymes and proteins — carrier of electrons(1, 2). Lipids in interaction with sterols, carotenoids and proteins are substances determining molecular structure, physical and chemical properties, and functional activity of membranes (3). Particularly in the chloroplast membranes, it could be advantageous to regulate lipid composition in response to environmental changes because it is shown that functional activities of these membranes depend upon their physical state A set of experiments indicated that high temperature action induced changes dependent upon the resistance of plants, heat exposure, and humidity of soil and air (4, 5).

Antistressor Impact Upon Carotenoids Content and Lipid Peroxidation in Winter Wheat Photosynthetic Tissues

Peroxidation is widely thought to be responsible for membrane deterioration during water stress (1). Superoxide radicals and their highly reactive derivates, hydroxyl radical and singlet oxygen, are known to be the main mediator of peroxidative damage to various cellular components such as membrane fatty acids, proteins, nucleic acids and chlorophyll. Peroxidation activity increase in soft plants while water deficit action was observed by many authors. (2, 3). Antioxidants can suppress free radical reactions and carotenoids belong to the compounds with this ability. The function of carotenoids in chloroplasts is now well established (4), especially carotenes, as a singlet oxygen quencher and scavenger of free radicals. On the other side, it is known the effect of carotenoids considered similar to that of cholesterol in animal cell membranes. Highly unsaturated lipid membranes are a very sensitive target for the destructive action of singlet oxygen and free radicals. Penetration on these species deeply into membranes hydrophobic interior should obviously be limited with decreased fluidity of the membrane regions adjacent to polar lipid head group zone (5).