[Fluorescent Indices of Bean Leaves Treated with Sodium Fluoride].

It is shown that the treatment of bean leaves with NaF in concentration of 10(-2) M resulted in the alteration of fluorescent indices registered by the method of pulse fluorimetry. Fluorescent parameters F(0) and F(m) decreased, but the ratio F(v)/F(m) = (F(m) - F(0))/F(m), characterizing the maximal photochemical activity of photosystem II remained invariable. Photochemical fluorescence quenching (qP) was higher than in control during the first minutes of illumination with the actinic light, and it markedly decreased with the following illumination. Nonphotochemical quenching (qN), in contrary, decreased at the beginning of illumination, and then increased. Photosynthetic activity as characterizing by the ratio (F(M) - F(T))/F(T) reduced after the leaf treatment with NaF. Results obtained are interpreted proceeding, on the one hand, from the influence of NaF on redistribution of excitation energy between photosystem II and photosystem I and its inhibitory effect on the ATPase complex and Kalvin-Benson cycle, on the other.

[Luminescent and physiological indices of triticale under the treatment of seeds with growth regulators].

It is shown that the before-sowing treatment of triticale seeds with growth regulators epin and zircon resulted in the increase in the F742/F686 ratio of the stationary fluorescence intensities of the plant leaves at the wavelength bands, 742 and 686 nm, corresponding to the maxima in the leaf fluorescence spectrum. Triticale under the treatment of seeds with growth regulators showed higher chlorophyll content, higher productivity and higher indices of the crop yield.

[Biophysical methods of ecological monitoring. Photosynthetic characteristics of tree plants growing in Moscow city].

In this work, we studied an influence of ecological factors (a distance from the highway) on photosynthetic characteristics of leaves of four species of tree plants growing in Moscow city. Photosynthetic activity of leaves was assayed by instrumental methods of probing the functional state of photosynthetic apparatus, using electron paramagnetic resonance method for measuring the kinetics of photooxidation of P700 centers, thermoluminescence, and slow induction of chlorophyll fluorescence. It has been shown that kinetic parameters of the induction curves, as measured from the kinetics of photooxidation of P700 and slow induction of chlorophyll fluorescence in dark-adapted leaves, are sensible to variations of plant growing conditions. These parameters can be used as informative characteristics for ecological monitoring of the environment.

[Luminescence characteristics of strawberry leaves in early stages of their injury by arachnoidal mite].

In this work, we have investigated how the luminescence characteristics and a total content of antioxidants in leaves of strawberry (Fragaria x ananassa Duch.) change after infestation of plants by spider mite (Tetranychus atlanticus McGregor). At the earlier stage of plant injury, the chlorophyll concentration remained unchanged. However, the total amount of antioxidants decreased and the intensity of high-temperature band (60 divided by 100 degrees C) of thermoluminescence increased, indicating a degradation of membrane lipids caused by oxidative stress. In infected leaves, the light-induced rise of non-photochemical quenching of chlorophyll fluorescence was slower, while the relaxation of non-photochemical quenching in the dark was faster than in control samples of leaves. These data might indicate that the thylakoid membranes in infested leaves were more permeable for ions than in control leaves.

[Slow fluorescence induction and productivity of barley treated with supercritical fluid extract of amaranth].

It is shown that treatment of barley plants with supercritical fluid extract of amaranth results in the increased fluorescence parameter (F(M) - F(T))/F(T) of slow fluorescence induction curve of the leaf. Barley treated with the extract showed higher productivity and higher indices of the yield.

[Slow fluorescence induction and CO2-exchange in bean leaves treated with Reynoutria sachalinensis extract].

It has been shown that the treatment of bean seedlings with a water extract of Reynoutria sachalinensis increases visible photosynthesis and the activity of dark respiration of plants. The increase in CO2-uptake under relatively high light illumination (10000 1x) correlates with an increase in the fluorescence parameter (F(M) - F(T))/F(T).

[Study of the cholinesterase active site using a fluorescent probe]. / Issledovanie aktivnogo tsentra kholinesterazy s ispol'zovaniem fluorestsentnogo zonda.

We studied fluorescence of 9-amino-1,2,3,4-tetrahydroacridine hydrochloride (tacrine) in the presence of serum cholinesterase. Quenching of tacrine fluorescence dependent on cholinesterase activity has been revealed. A quenching mechanism is proposed; it includes formation of a complex and charge transfer mediated by excited tacrine molecule as well as indole of tryptophan residue from the periphery of cholinesterase active site.

[Theoretical analysis of inductive effects in higher plant photosynthesis]. / Teoreticheskoe izuchenie induktsionnykh éffektov v fotosinteze vysshikh rastenii.

The proposed mathematical model of the light stages of photosynthesis in higher plants takes into account the regulatory process of excitation energy redistribution between photosystems depending on the redox state of electron carriers. Nonmonotonic changes in the intensity of pigment fluorescence upon switching on the excitation light (delayed fluorescence induction) are described. The time required for fluorescence to reach its peak intensity and the degree of fluorescence quenching depending on light intensity are analyzed. Th kinetics of light-induced changes in EPR I signal upon switching from the far-red to white light is simulated.

[Luminescent indicators in various parts of wheat leaves in ontogenesis]. / Liuminestsentnye pokazateli v raznykh uchastkakh lista pshenitsy v ontogeneze.

A comparative study of slow fluorescence induction, fluorescence spectra, thermoluminescence, photosynthetic activity and chlorophyll content in ontogenesis of wheat seedlings (Triticum aestivum L, cv. Yubileinayd) grown in the laboratory conditions was carried out. It was shown that (FM-FT)/FT values of slow fluorescence induction increased with the age of leaf part, reached a maximum (for 2-week-old seedlings), and then decreased. Changes in (FM-FT)/FT positively correlated with the changes in photosynthetic activity per chlorophyll unit (delta O2/(delta t.chlorophyll)); the coefficient of correlation r = 0.84, p > 0.999. The F685/F730 ratio of the intensities of fluorescence spectrum decreased with the increase in chlorophyll content. The relative light sum SA/S(tot) of band A of thermoluminescence changed in the same direction as delta O2/(delta t-chlorophyll), the relative light sum (SC/S(tot) of band C of thermoluminescence decreased during leaf maturation. The regularities revealed in the experiments are discussed in terms of changes in the structural and functional organization of the photosynthetic apparatus known from the literature.

[Antifungal activity of aqueous extracts from the leaf of cowparsnip and comfrey]. / Fungitoksicheskaia aktivnost' vodnykh ékstraktov iz list'ev borshchevika i okopnika.

We found that extracts from the leaves of medicinal comfrey and cowparsnip strongly inhibit the germination of Erysiphe graminis conidia and uredospores of Puccinia graminis. Spraying wheat seedlings with these extracts, in contrast to the irrigation of soil, markedly diminished infection in plants with powdery mildew. Antifungal activity in vitro and protective activity (when plants were sprayed) correlated with the level of phenolic compounds in these extracts. Experiments with healthy plants have demonstrated that the photosynthetic apparatus of wheat plants is stimulated by extracts. Spraying seedlings with the extracts resulted in an increased rate of O2 evolution calculated per unit of chlorophyll, an increase in the ratio (FM-FT)/FT in the experiments that recorded slow fluorescence induction, an increase in the relative light intensity of band A, and a decrease of relative intensity of band C in experiments with thermoluminescence of wheat leaves. These results provide evidence that the protective activity of comfrey and cowparsnip extracts is associated with their action on the pathogenic fungus and with the activation of natural defense reactions of the host plant.

[Changes in induction of slow fluorescence in leaves of maple located near urban highways]. / Izmenenie medlennoi induktsii fluorestsentsii list'ev klena vblizi transportnykh magistralei.

The slow fluorescence induction parameter FM/FT was measured for green leaves from maple trees grown in the park, depending on the distance (5-65 m) between the tree and the highway cross. We concluded that the decrease in the value of FM/FT for trees grown in the vicinity of the road cross was caused by exhaust gases.

[Characteristics of the leaf photosynthetic machinery in broad bean grown in zinc chloride aqueous solutions]. / Osobennosti fotosinteticheskogo apparata list'ev bobov, vyrashchennykh na vodnykh rastvorakh khlorida tsinka.

The structural and functional characteristics of bean leaves (the content of chlorophyll, the rate of oxygen production, the slow fluorescence induction, and light-induced changes in the EPR signal I from oxidized reaction centers P700+) were investigated to obtain insight into the mechanism of influence of zinc chloride on the photosynthetic apparatus. Seedlings were grown on hydroponic medium containing ZnCl2 at concentrations from 10(-7) to 10(-3) M. At low concentrations of ZnCl2, a decrease in the content of chlorophyll per one unit of leaf mass was observed, while the rate of oxygen production per chlorophyll was increased. High concentrations of ZnCl2 in the hydroponic medium caused the slowed down the plant development and inhibited the light-induced production of oxygen. The changes in biophysical characteristics of leaves the parameter FM/FT of the slow fluorescence induction, and kinetics of redox transients of P700 induced by ZnCl2 were of similar character and correlated with the changes in photosynthetic activity. The data obtained demonstrate that structural and functional changes in the photosynthetic apparatus induced by the variations of growth conditions have adaptive character.

[Various luminescence characteristics of allocytoplasmic wheat hybrids]. / Nekotorye liuminestsentnye kharakteristiki allotsitoplazmaticheskikh gibridov pshenitsy.

Comparative studies of thermoluminescence and slow fluorescence induction were carried out on leaves of allocytoplasmic hybrids and standard regionalized wheat (cultivar Zarya). There are differences in luminescence indices between these objects correlated to the thermoluminescence and slow fluorescence induction methods. These differences allow estimation of the functional activity of the photosynthetic system. All studied allocytoplasmic hybrids exceeded the standard wheat in both luminescence indices FM/FT (slow fluorescence induction) and SA/Stot (thermoluminescence) and productivity (height of seedlings, number of ears and grains, grain mass, etc.). The highest values of FM/FT and SA/Stot and the lowest value of SC/Stot were recorded in the allocytoplasmic hybrid Igen 3 x Mironovskaya 808, which is characterized by the highest productivity.

[Effect of inorganic phosphate on photosynthesis in bean leaves]. / Vliianie neorganicheskogo fosfata na rabotu fotosinteticheskogo apparata list'ev bobov.

It was shown that raising pod seedlings by the hydroponics method on KH2PO4 solutions at concentrations between 10(-7) and 10(-5) M leads to an increase in the rate of oxygen release (delta O2/delta t), with the chlorophyll content in leaves being unchanged. The values of the parameters FM/FT of slow fluorescence induction and B/A of photoinduced changes in ESR1 signals from pod leaves correlate with the delta O2/delta t value.

[Adaptation to darkness and far red light of leaves of higher plants in conditions of oxygen deficiency]. / Adaptatsiia k temnote i dal'nemu krasnomu svetu list'ev vysshikh rastenii v usloviiakh nedostatka kisloroda

The adaptation process of the leaves of higher plants to dark and far red light under the conditions of oxygen deficiency was investigated. The reaction constant for the oxidation of the electron carrier molecules with oxygen in the dark was obtained and found to be 1.4 with 10-3 M-1 min-1.