[NaCl-induced photoinhibition and the recovery of the photosynthetic activity of katG- mutant of the cyanobacterium Synechocystis sp. PCC 6803].

The joint effects of 0.5 M NaCI and light of different intensities on the activity of the photosynthetic apparatus and ATP contents in cells of the katG- mutant of cyanobacterium Synechocystis sp. PCC 6803 have been studied.

[Orange-red light reduces the inhibition by UV-A of the proliferation of rat fibroblasts and influences their attachment in a dose-dependent fashion].

The effects of ultraviolet-A (UV-A, lambdam = 365 nm) and orange-red light (lambdam = 625 nm) on the attachment and proliferation of embryonic skin-muscle rat fibroblasts were investigated. It was found that orange-red light (ORL) produces both the stimulatory and inhibitory actions on the attachment and proliferation of fibroblasts, whereas UV-A radiation caused only the inhibition of the processes. Upon consecutive irradiation in both variants: ORL --> UV and UV --> ORL, the synergistic effect of the inhibitory action in both spectral regions was observed.

[Effect of oxidative stress inductors on the photosynthetic apparatus in cyanobacterium Synechocystis sp. PCC 6803 Prq20 mutant resistant to methyl viologen].

The damaging effect of oxidative stress inductors: methyl viologen, benzyl viologen, cumene hydroperoxide, H2O2, menadion, and high irradiance on the photosynthetic apparatus of cyanobacterium Synechocystis sp. PCC 6803 in cells of the wild type strain and the methyl viologen-resistant Prq20 mutant with the disrupted function of the regulatory gene prqR has been investigated by measuring the delayed fluorescence of chlorophyll a and the rate of CO2dependent -O2 gas exchange. It has been shown that the damage to the photosynthetic apparatus in the Prq20 mutant as compared with the wild type was less in the presence of methyl viologen and benzyl viologen.

[Low radiance in the region of wavelengths 620-660 nm reduces the UV-B-induced damage to photosystem II in spinach leaves].

The effect of monochromatic preirradiation in the region of wavelengths 550-730 nm on the parameters of variable and delayed fluorescence in primary spinach leaves irradiated with UV-B was investigated. It was shown that irradiation of leaves with UV-B at lambda(M) = 300 nm reduced photoinduced changes in variable and delayed fluorescence as well as increased the half rise-time of maximum fluorescence. Preirradiation in the region of 620-660 nm (I = 2-4 W x m(-2)) reduced partly the damage to photosystem II induced by UV-B, whereas preirradiation at lambda(m) = 550, 600, 700, and 730 nm had no significant influence.

[After effect of heat shock on induction of fluorescence and low temperature fluorescence spectra of wheat leaves].

The dynamics of restoration of variable and millisecond delayed fluorescence of chlorophyll a, as well as low-temperature fluorescence spectra at 77 K in leaves of 11-day-old wheat seedlings subjected to heat shock (41.5 degrees C, 20 min) and cultivated for 4 days under white light of different intensity was investigated. A comparative analysis of changes in variable, delayed, and low-temperature fluorescence of chlorophyll a depending on light intensity and the proteolitic activity in leaf homogenates during the restoration of the seedlings was carried out.

[Effect of choline chloride on photosynthetic oxygen release and variable and delayed fluorescence of chlorophyll in Chlamydomonas reinhardtii cells].

The influence of the growth retardant chlorocholine chloride on the rate of photosynthetic oxygen evolution and the induction of chlorophyll fluorescence in unicellular green algae Chlamydomonas was studied depending on concentration and the time of cell growth. It was shown that low concentrations chlorocholine chloride (0.02 g/l) affected insignificantly the photosynthesis and chlorophyll fluorescence.

[Choline chloride effect on chloroplast ultrastructure and cell growth in Chlamydomonas reinhardtii].

The influence of growth retardant choline chloride (0.02, 0.2 and 2 g/l) on cell size and division as well as chlorophyll accumulation and chloroplast ultrastructure of unicellular green algae Chlamydomonas was studied.

[Quenching of chlorophyll and pheophytin fluorescence with fucoxanthin].

Quenching of chlorophyll a and pheophytin a fluorescence with fucoxanthin in acetone and n-hexanole at room temperature was investigated. The relationship between fluorescence yield and concentration of the quencher is subject to Stern--Folmer relation. The velocity constants were calculated and the efficiency of fluorescence quenching was determined.