Influence of clinorotation on some parameters of photosynthetic apparatus.

This study aimed to examine the electron transport rates in the thylakoids, isolated from leaves of pea plants grown under clinorotation and in vertical control, to measure the chlorophyll a/b (Chl a/b) ratio in such thylakoids and in photosystem I (PSI) particles isolated from them, to elucidate if there are any differences in changes of PS II activity in thylakoids and Chl a/b ratio in PS I particles under phosphorylation of polypeptides of thylakoid pigment-protein complexes.

[Variability of DNA methylation in sugar beet morphogenesis].

The state of DNA methylation in green leaves and etiolated seedlings of sugar beet (Beta vulgaris L.) were compared. Using methylsensitive enzymes of restriction the site-specificity of DNA methylation was shown.

Some characteristics of photosynthetic apparatus under conditions of spaceflight.

During colonization of space by humans, the bioregenerative life-support systems on board the space ships will require the plants with a highly efficient photosynthesis, a process producing food and O2 and removing CO2-Therefore, in recent years the scientists increasingly focus the their attention to study on photosynthetic apparatus of plants grown in space. Although the available data are quite scanty and, at times, controversial, it is Considered that the space grown plants differ from around control plants by growth and development, many structural and functional indices and metabolism. Data exist showing changes in the chlorophyll (Chl) content, structure and number of chloroplasts in the cell, swelling of thylakoids and decrease in the number and size of starch grains in the chloroplasts (for reviews, see Halstead and Dutcher, 1987; Kordyum, 1997).

Effect of clinostating on photosynthetic apparatus of pea plants.

The photosynthetic membrane composition and low temperature fluorescence spectra were analyzed for pea chloroplasts from control and clinostated plants. Clinorotation induces a decrease in the amount of the oligomeric form of the light-harvesting chlorophyll a/b complex (LHCII) and an increase of its monomeric form. Some changes in organization of photosystem 1 (PS1) complex were revealed as well.

Decomposition of acetylcholine with ethylene formation in vitro. Possible free radical mechanism of acetylcholine action.

Experiments were designed to investigate the effect of different buffered solutions, Fenton reagent and hydrogen peroxide on acetylcholine decomposition with ethylene formation. The data of the present study suggests that acetylcholine is decomposed in vitro to form ethylene by interacting with the free radicals or in the Hofmann's splitting reaction. It is found that free radicals are required for the fast decomposition of acetylcholine to form ethylene.

Functional cybrid plants of Lycopersicon peruvianum var 'dentatum ' with chloroplasts of Lycopersicon esculentum.

 Fertile cybrid plants of three subclones, B1A, B3A, B4A were regenerated from the single colony obtained after the fusion of mesophyll protoplasts of plastome chlorophyll-deficient mutant Lycopersicon peruvianum var 'dentatum' (line 3767) and γ-irradiated mesophyll protoplasts of L. esculentum (cv 'Quedlinburger Frühe Liebe'). Cytogenetic, isozyme, RAPD, morphological and restriction analyses all showed that the subclones had the nuclear genome of L.

[Variability of RNA in morphogenesis of sugar beet and sunflower leaves].

We investigated the developmental gene expression patterns of Beta vulgaris L. using DNA: RNA hybridization reactions. We found that 2,100 and 900 diversive poly(A)+mRNA were synthesized while 430 and 4,000 diversive poly(A)+mRNA were disappeared during greening in cells of cotyledons and during senescence in cells of yellowing leaves respectively.

[Effect of low temperature on electron transport in plant mitochondria respiratory chain].

The etiolated 2.5-day winter wheat sprouts were chilled at 3 degrees C during 24 to 144 hours. After 24 h cooling, shoot intact mitochondria showed a high degree of activation of the alternative oxidase, which was measured as sodium azide and benzohydroxamate sensitivity of the organelles respiration with succinate as a substrate.

[Characterization of amino acid composition of lectin from noduleless soybean].

The amino acid composition of lectin from noduleless soybean has been investigated. It is shown that contents of threonine, serine and proline are higher but contents of tyrosine, phenylalanine and histidine are lower as compared with those in lectin from common soybean. The conclusion is made about the significance of amino acid composition of soybean lectin for its symbiotic properties.

[Biochemical characterization of noduleless soybean lectins].

The comparative analysis of activity and hydrocarbon specificity of lectins from common soybean and soybean in which roots the nodules do not form has been carried out. It was shown that the root lectins possesses the less activity in comparison with the seed lectins. The both kinds of lectins most specifically link with mannitol.

[The peculiarities of pigment-protein composition of intergranular thylakoid fragments from maize chloroplasts].

The pigment-protein composition of two fractions of intergrana fragments from maize inbred lines F 7 and II 346 chloroplast had been investigated. It was shown that under electrophoretic separation of fraction 70,000 g from both lines and fraction 100,000 g from line F 7 the new band of pigment-protein complexes had been observed. It was determined that its polypeptide composition is the same as light-harvesting complex of PS II one, but it differs by low electrophoretical mobility.

[Changes in pigment-protein composition of maize subchloroplast fragment fragments under conditions of phosphorylation].

The pigment-protein composition of two mesophyl chloroplast fractions from maize inbred lines II 346 and F 7 and its alterations under phosphorylation have been studied. In virtue of differences in the composition of photosystem II (PS II) and PS II light-harvesting chlorophyll a/b-protein complex (LHC II) it has been shown that fraction 70,000 g origins from grana marginal regions and fraction 100,000 g is from stroma lamellae. Migration of LHC II occurs both in marginal and stromal fractions but PS II migration, only in marginal fractions.

Changes in lipid composition of Photosystem 1 particles from thylakoids phosphorylated under reductive or anaerobic conditions.

Changes in lipid composition of Photosystem 1 (PS 1) particles isolated from thylakoids phosphorylated under reductive or anaerobic conditions have been studied. Under reductive conditions, there was an increase in monogalactosyldiacylglycerol containing highly saturated fatty acids and phosphatidylglycerol containing transhexadecenoic fatty acid. Under anaerobic conditions, the amount of all lipid classes was increased.

Fluorescence studies on interaction between phospho-LHC II and subchloroplast Photosystem 1 preparations.

Chloroplast proteins were phosphorylated under two test conditions: 'white light' irradiance alone and 'white light' irradiance with the addition of glucose and glucose oxidase, used to produce an anaerobic medium. The interaction of phospho-LHC II with Photosystem 1 (PS 1) was studied for two types of PS I preparation. Changes in the chlorophyll a/b ratio and the ratio of 650 and 680 nm band intensities (E650/E680) in fluorescence excitation spectra were used in calculating the phospho-LHC II portion which became associated with PS 1.

Lysophosphatidylcholine specifically stimulates plasma membrane H(+)-ATPase from corn roots.

The plasma membrane H(+)-ATPase activity from corn seedling roots is shown to be stimulated 3- to 4-fold by the addition of lysophosphatidylcholine (lysoPC). This effect clearly differs from that of other detergents by both the magnitude and the absence of inhibition at higher concentrations. LysoPC decreases the apparent Km for MgATP, increases Vmax of the ATPase reaction but does not change its pH optimum.

Analysis of chloroplast and mitochondrial DNAs in asymmetric somatic hybrids between tobacco and carrot.

Chloroplast and mitochondrial DNAs have been examined by comparison of restriction enzyme patterns in asymmetric hybrid plants, resulting from the fusion between leaf mesophyll protoplasts of Nicotiana tabacum (Solanaceae), and irradiated cell culture protoplasts of Daucus carota (Umbellifereae). These somatic hybrids with normal tobacco morphology were selected as a consequence of the transfer of methotrexate and 5-methyltryptophan resistance from carrot to tobacco. The restriction patterns of chloroplast DNAs in somatic hybrids were indistinguishable from the tobacco parent.