[Study of the effect of methylmercury and copper ions on primary photosynthesis processes in the green algae Chlamydomonas moevusii using the parameters of kinetic curves of the variable of chlorophyll fluorescence].

The effect of methylmercury and copper ions on the kinetics of light induction and dark relaxation of the variable of chlorophyll a fluorescence has been studied on cultures of the microalgae Chlamydomonas moevusii. It was shown that the toxicants added at concentrations that induce no decrease in photochemical activity of PS II (F(v)/F(M)) affect the electron transport on the acceptor side of PS II, the nonphotochemical quenching of excitation in the antenna, and the reoxidation of the quinone pool. At low concentrations, methylmercury produced a more toxic effect. The results obtained indicate that this approach can be used for detecting the changes in plant and algae cells at the early stages of the action of toxicants.

[Fluorescence parameters of chlorophyll in leaves of caules plants in different environmental conditions].

The functional state of medicinal plants of Convallaria majalis L., Vaccinium vitis-idaeae L., Arctostaphylos uva-ursi L. in connection with heavy metal accumulation in their leaves under man impact was studied by the pulse-amplitude-modulation (PAM) fluorometric method. The relative yield of variable fluorescence (F(v)/F(m)), induction of fluorescence of chlorophyll, and fluorescence quenching processes in leaves at different distances from the local Kirov-Sovetsk, Kirov-Omutninsk road in Kirov region were analyzed. Changes in biophysical characteristics with the increasing content of heavy metals in leaves were demonstrated. The most informative characteristic is F(v)/F(m). Its value correlates with the activity of the photosynthetic apparatus and reflects the potential effeciency of photosynthesis. The better are the environmental conditions of plant growth, the higher is the F(v)/F(m) ratio and the lower is its average statistical deviation. Fluorescence induction curves do not always vary in shape under our ecological conditions, indicating relatively favorable conditions at places of plant growth investigated. The rate of the environmental pollution in the investigated region is not critical, since the content of heavy metal in leaves does not change considerably with the distance from the road.