The influence of Lindane on net phytoplankton (mainly diatoms) in samples of waters from the Antarctic was investigated for 24 hours from the introduction of ɣ HCH 0,02 and 2 ppm into the environment. Changes in intensity of 14C incorporation in the light and in rate of release of 14C by the cells in the dark during consecutive light/dark periods were measured. The effect of two different Lindane concentrations in diatoms occurred 16 hours after introduction of the compound into the environment and was independent of concentration. The effect was manifested by delayed induction of photosynthesis following the dark period and also by changes in dynamic equilibrium between carbon assimilation and dissimilation. The presence of Lindane clearly stimulated 14C incorporation in the light and also enhanced the participation of 14C incorporation in overall CO2 exchange in the dark.

Cucumber (Cucumis sativus L. cv. Dar) leaves exposed to UV-B irradiation at a biologically effective dose of 9.5 kJ m-2d-1 showed decreased chlorophyll fluorescence parameter values versus the control; in peppermint (Mentha piperita L. cv. Asia) leaves those values were almost unchanged after treatment. Fv/Fo and Rfd were reduced more than other values, indicating inhibition of the oxygen-evolving complex and cooperation between the light and dark photosynthesis reactions as the primary targets of UV-B. The photosynthetic electron transport rate showed less change directly after irradiation, but after 24 h of recovery it was reduced to 50% of the control. Generally, photosystem II of peppermint leaves appeared more tolerant to the applied UV-B radiation than in cucumber leaves.

The experiment on Zea mays L. cv. Landmark (F1) plants was performed in a greenhouse with UV-B (305–315 nm). The pots with plants were divided into four groups: the first and the second groups were grown, respectively, at low (1.0 kJ m-2 d-1) and high (3.0 kJ m-2 d-1) biological effective dose of UV-B radiation. Half of the pots of each group were sprayed with 0.1% solution of Asahi SL (the third and fourth groups). The intensity of photosynthesis and transpiration, chlorophyll fluorescence, the content of UV-absorbing compounds and radical scavenging activity were measured using DPPH after four and six weeks of UV-B radiation. After six weeks of irradiation with a higher UV-B dose both flavonoid content and antioxidant activity increased by 112% and by 44%, respectively, compared to the plants grown at the lower dose. The plants treated with Asahi SL and exposed to the high dose of UV-B had the content of flavonoids 80% higher than the control ones. Asahi SL decreased scavenging activity in both groups of plants by 17% and 32%, respectively, in comparison with the untreated plants. The intensity of net photosynthesis, the transpiration rate and chlorophyll fluorescence parameters (Fv/Fo, ETR, Rfd) did not differ in most of variants.

Since plant responses to selenium nanoparticles (nSe) had not been clarified, this study was carried out to evaluate the effects of nSe (10 and 100 μM) on photosynthesis performance, ion homeostasis, antioxidant system, and phenylpropanoids in strawberry exposed to salt stress. Inductively Coupled Plasma-Mass Spectroscopy analyses indicated that foliar-applied nSe can be taken up by leaves and trans-located to roots. Salinity led to an increase in Na concentration and reductions in Ca and K contents which were relieved by the nSe applications. Moreover, the nSe treatment at 10 μM alleviated the NaCl-induced lesion to PSII functioning, contributing to improvement in water-splitting complex (Fv/Fo) under salinity. The exposure to nSe at a concentration of 100 µM exhibited a moderate stress, determined by the increases in hydrogen peroxide (H2O2) and lipid peroxidation rate (membrane integrity index). The nSe10 treatment increased catalase activity and phenylpropanoid derivatives contents (salicylic acid, catechin, and caffeic acid) and decreased the content of oxidants under salinity condition. Consequently, nSe utilization at a suitable dose can be an effective method to alleviate signs of salt stress via improvements in photosynthesis, ion hemostasis, photosynthesis performance, salicylic acid (a vital signaling defensive hormone), and antioxidant machinery.

In order to evaluate morphological and physiological traits related to drought tolerance and to determine the best criteria for screening and identification of drought-tolerant genotypes, we grew two tolerant genotypes (MCC392, MCC877) and two sensitive genotypes (MCC68, MCC448) of chickpea under drought stress (25% field capacity) and control (100% field capacity) conditions and assessed the effect of drought stress on growth, water relations, photosynthesis, chlorophyll fluorescence and chlorophyll content in the seedling, early flowering and podding stages. Drought stress significantly decreased shoot dry weight, CO2 assimilation rate (A), transpiration rate (E), and Psii photochemical efficiency (Fv/Fm) in all genotypes. In the seedling and podding stages, Psii photochemical efficiency was higher in tolerant genotypes than in sensitive genotypes under drought stress. Water use efficiency (WUE) and CO2 assimilation rate were also higher in tolerant than in sensitive genotypes in all investigated stages under drought stress. Our results indicated that water use efficiency, A and Fv/Fm can be useful markers in studies of tolerance to drought stress and in screening adapted cultivars of chickpea under drought stress.

The reports of Intergovernmental Panel for Climate Change indicate that the growing emission of greenhouse gases, produced from the combustion of fossil fuels, mainly carbon dioxide, leads to negative climate changes. Therefore, the methods of mitigating the greenhouse gases emission to the atmosphere, especially of carbon dioxide, are being sought. Numerous studies are focused on so-called geological sequestration, i.e. injecting carbon dioxide to appropriate geological strata or ocean waters. One of the methods, which are not fully utilized, is the application of appropriate techniques in agriculture. The plant production in agriculture is based on the absorption of carbon dioxide in the photosynthesis process. Increasing the plant production directly leads to the absorption of carbon dioxide. Therefore, investigation of carbon dioxide absorption by particular crops is a key issue. In Poland, ca. 7.6 mln ha of cereals is cultivated, including: rye, wheat, triticale, oat and barley. These plants absorb approximately 23.8 mln t C annually, including 9.8 mln t C/yr in grains, 9.4 mln t C/yr in straw and 4.7 mln t C/yr in roots. The China, these cereals are cultivated on the area over 24 mln ha and absorb 98.9 mln t C/yr, including 55 mln tC/yr in grains, 36 in straw, and 7.9 mln t C/yr in roots. The second direction for mitigating the carbon dioxide emission into the atmosphere involves substituting fossil fuels with renewable energy sources to deliver primary energy. Cultivation of winter cereals as cover crops may lead to the enhancement of carbon dioxide removal from the atmosphere in the course of their growth. Moreover, the produced biomass can be used for energy generation.