Hydrodynamic cavitation-enhanced activation of sodium percarbonate for estrogen removal.

The present paper investigated the potential of hydrodynamic cavitation (HC) as an effective tool for activating sodium percarbonate (SPC). The method's efficiency was demonstrated by effectively removing estrogens, which are pollutants that have adverse impacts on aquatic ecosystems. The effects of the SPC concentration, temperature of solution, and cavitation time were evaluated. After SPC/HC treatment, the removal of estrogens was monitored by liquid chromatography-tandem mass spectrometry (LC -MS/MS). Already after 4 s of treatment and 24 h of reaction time, more than 97% of estrogens (initial concentration of 300 ng/L) were removed. The effect of post-treatment time is not considered in several papers, even though it seems to be crucial and is discussed here. The results were supported by the values of degradation rate constants, which fit the pseudo-first-order kinetic model. We also verified that HC alone was not effective for estrogen removal under the selected conditions. The sustainability of the SPC/HC system was evaluated based on electric energy per order calculation. The combination of SPC and HC is a promising approach for rapidly degrading micropollutants such as estrogenic compounds without the need for additional technological steps, such as pH or temperature adjustment.

Potential toxicity of Schisandra chinensis to water environment: acute toxicity tests with water crustaceans.

Fruits of Schisandra chinensis, an East Asian liana plant, are currently more and more used to produce nutrient supplements that positively affect human health due to the content of various secondary metabolites. On the other hand, these substances because of their bioactivity can cause possible allelopathic or toxic effects concerning other organisms (algae, plants, animals). But the ecotoxicological properties of S. chinensis outside its area of origin have yet to be sufficiently verified. Two crustaceans, Daphnia magna and Thamnocephalus platyurus, were selected as model aquatic organisms to test the potential impact of S. chinensis active compounds on the aquatic environment. Crude water extract from S. chinensis fruits, simulating the natural leakage of active substances in water, was tested in treatments from 0.0045 to 45 mg/L (according to the content of schisandrin as the dominating lignan). Effective concentration (EC50) causing 50% lethal effect for D. magna was established to 0.0448 mg/L after 24 h and 0.0152 mg/L after 48 h. EC50 for T. platyurus reached 0.4572 mg/L after 24 h, i.e. more than ten times higher than for D. magna. This study showed that the potential environmentally relevant concentrations of S. chinensis bioactive compounds could represent a severe risk to aquatic ecosystems.

Ambiguous changes in photosynthetic parameters of Lemna minor L. after short-term exposure to naproxen and paracetamol: Can the risk be ignored?

Non-steroidal anti-inflammatory drugs (NSAID) are recently monitored in the aquatic environment. Naproxen (NPX), paracetamol (PCT) and their transformation products can influence the biochemical and physiological processes at the sub-cellular and cellular levels taking part in the growth and development of plants. This study aimed to compare the effects of NPX and PCT, drugs with different physico-chemical properties, on the growth and photosynthetic processes in Lemna minor during a short-term (7 days) exposure. Although duckweed took up more than five times higher amount of PCT as compared to NPX (275.88 µg/g dry weight to 43.22 µg/g when treated with 10 mg/L), only NPX limited the number of new plants by 9% and 26% under 1 and 10 mg/L, respectively, and increased their dry weight (by 18% under 10 mg/L) and leaf area per plant. A considerable (by 30%) drop in the content of photosynthetic pigments under 10 mg/L treatment by both drugs did not significantly affect the efficiency of the primary processes of photosynthesis. Values of induced chlorophyll fluorescence parameters (F0, FV/FM, ΦII, and NPQ) showed just a mild stimulation by PCT and a negative effect by NPX (by up to 10%), especially on the function of photosystem II and electron transport in both intact duckweed plants and isolated chloroplasts. Lowered efficiency of Hill reaction activity (by more than 10% under 0.1 - 10 mg/L treatments) in isolated chloroplasts suspension proved the only inhibition effect of PCT to primary photosynthetic processes. In intact plants, higher treatments (0.5 - 10 mg/L) by both NPX and PCT induced an increase in RuBisCO content. The results prove that the potential effect of various drugs on plants is hard to generalise.

Bioactive compounds from Schisandra chinensis - Risk for aquatic plants?

Schisandra chinensis is a potential plant for production of nutrient supplements due to adaptogens content. The dominant bioactive substance, lignan schisandrin, has positive effects on human health, but it can cause possible allelopathic effects in relation to other plants. S. chinensis is not native to European ecosystems, and its ecotoxicological properties have not been verified yet. Lemna minor was selected as a model aquatic plant to test its potential impact on the aquatic environment. Crude water extract from S. chinensis fruits, simulating the natural soaking of active substances in a surface water body, was used in treatments from 0.045 to 45 mg/L (according to the content of schisandrin as the dominating lignan). During seven days of cultivation, the growth (number of plants, leaf area, fresh weight) and photosynthetic activity of L. minor fronds were assessed. In low treatments (0.045 and 0.09 mg/L), the extract of S. chinensis did not cause any changes in duckweed growth parameters or photosynthetic performance. Higher treatments (0.45 and 0.9 mg/L) caused significant limitations in plants' number, total leaf area, and fresh weight. The photosynthetic parameters (basal chlorophyll fluorescence, quantum yields) were affected only by 0.9 mg/L. The highest treatment, 45 mg/L, exhibited extreme toxicity to duckweed plants causing their death during the first five days of cultivation. Schisandrin and other bioactive substances extractable from S. chinensis fruits can negatively impact water biota in the case of massive contamination of surface water.

Pea root responses under naproxen stress: changes in the formation of structural barriers in the primary root in context with changes of auxin and abscisic acid levels.

Pharmaceuticals belong to pseudo-persistent pollutants because of constant entry into the environment and hazardous potential for non-target organisms, including plants, in which they can influence biochemical and physiological processes. Detailed analysis of results obtained by microscopic observations using fluorescent dyes (berberine hemisulphate, Fluorol Yellow 088), detection of phytohormone levels (radioimmunoassay, enzyme-linked immune sorbent assay) and thermogravimetric analysis of lignin content proved that the drug naproxen (NPX) can stimulate the formation of root structural barriers. In the primary root of plants treated with 0.5, 1, and 10 mg/L NPX, earlier Casparian strip formation and development of the whole endodermis circle closer to its apex were found after five days of cultivation (by 9-20% as compared to control) and after ten days from 0.1 mg/L NPX (by 8-63%). Suberin lamellae (SL) were deposited in endodermal cells significantly closer to the apex under 10 mg/L NPX by up to 75%. Structural barrier formation under NPX treatment can be influenced indirectly by auxin-supported cell division and differentiation caused by its eight-times higher level under 10 mg/L NPX and directly by stimulated SL deposition induced by abscisic acid (higher from 0.5 mg/L NPX), as proved by the higher proportion of cells with SL in the primary root base (by 8-44%). The earlier modification of endodermis in plant roots can help to limit the drug transfer and maintain the homeostasis of the plant.

Root response in Pisum sativum under naproxen stress: Morpho-anatomical, cytological, and biochemical traits.

Non-steroidal anti-inflammatory drugs as an important group of emerging environmental contaminants in irrigation water and soils can influence biochemical and physiological processes essential for growth and development in plants as non-target organisms. Plants are able to take up, transport, transform, and accumulate drugs in the roots. Root biomass in ten-days old pea plants was lowered by 6% already under 0.1 mg/L naproxen (NPX) due to a lowered number of lateral roots, although 0.5 mg/L NPX stimulated the total root length by 30% as against control. Higher section area (by 40%) in root tip, area of xylem (by 150%) or stele-to-section ratio (by 10%) in zone of maturation, and lower section area in zone of lateral roots (by 18%) prove the changes in primary root anatomy and its earlier differentiation at 10 mg/L NPX. Accumulated NPX (up to 10 µg/g DW at 10 mg/L) and products of its metabolization in roots increased the amounts of hydrogen peroxide (by 33%), and superoxide (by 62%), which was reflected in elevated lipid peroxidation (by 32%), disruption of membrane integrity (by 89%) and lowering both oxidoreductase and dehydrogenase activities (by up to 40%). Elevated antioxidant capacity (SOD, APX, and other molecules) under low treatments decreased at 10 mg/L NPX (both by approx. 30%). Naproxen was proved to cause changes at both cellular and tissue levels in roots, which was also reflected in their anatomy and morphology. Higher environmental loading through drugs thus can influence even the root function.

Detail investigation of toxicity, bioaccumulation, and translocation of Cd-based quantum dots and Cd salt in white mustard.

In this study, a model crop plant white mustard (Sinapis alba L.) was treated with an aqueous dispersion of silica-coated CdTe quantum dots (CdTe/SiO2 QDs) in a 72-h short-term toxicity test. The toxicity was established via measurements of (i) the root length and (ii) the chlorophyll fluorescence. These results were compared to two other sources of cadmium, free Cd ions (CdCl2) and prime un-shell nanoparticles CdTe QDs. Tested compounds were applied in concentrations representing 20 and 200 µM Cd. The uptake and translocation of Cd were investigated using inductively coupled plasma optical emission spectrometry (ICP-OES) and the spatial Cd distribution was investigated in detail applying laser induced breakdown spectroscopy (LIBS). The LIBS maps with a lateral resolution of 100 µm were constructed for the whole plants, and maps with a lateral resolution of 25 µm (micro-LIBS arrangement) were used to analyse only the most interesting parts of plants with Cd presence (e.g. root tips or a part crossing the root into the above-ground part). Our results show that the bioaccumulation patterns and spatial distribution of Cd in CdTe/SiO2 QDs-treated plants differ from the plants of positive control and CdTe QDs. Fluorescence microscopy photographs revealed that CdTe/SiO2 became adsorbed onto the plant surface in comparison to CdTe QDs. Further, a physico-chemical characterization of QDs before and after the test exposure showed only minor changes in the nanoparticle diameters and no tendencies of QDs for agglomeration or aggregation during the exposure.

High-pressure jet-induced hydrodynamic cavitation as a pre-treatment step for avoiding cyanobacterial contamination during water purification.

Due to specific physical properties, hydrodynamic cavitation (HC) is assigned to the powerful technologies for treating the biotic contamination in water including cyanobacteria. Contaminated water stream (CWS) can be cavitated directly by passing through some HC device, or indirectly when high-pressure jet stream (HPJS) is directed against its flow. Relatively small HPJS stream can thus treat a big volume of CWS in a short time or even work in continuous mode. Cyanobacteria floating in the CWS are forced to flow through the mixing cavitation zone. Within 2 h after single HC treatment, cyanobacterial cell suspensions showed disintegration of larger colonies and enhanced biomass sedimentation. Additional pre-treatment of CWS with low amounts of hydrogen peroxide (H2O2; 33, 66 and 99 µmol/L) enhanced the effect of HC and led to further inhibition of cyanobacterial photosynthesis (maximum quantum yield of photosystem II decreased by up to 60%). The number of cyanobacterial cells in the treated CWS decreased continuously over 48 and 72 h, though some cells remained alive and were able to recover photosynthetic activity. The technique proposed (direction of a HPJS against a CWS and pre-treatment with low H2O2 concentrations) provides (i) effective removal of cells from the water column, and (ii) reduced contamination by organic compounds released from the cells (especially cyanotoxins) as the cell membranes are not destroyed and the cells remain alive. This process shows potential as an effective pre-treatment step in water purification processes related to cyanobacterial contamination.

Possible use of a Nicotiana tabacum 'Bright Yellow 2' cell suspension as a model to assess phytotoxicity of pharmaceuticals (diclofenac).

Growth and developmental changes in plants induced by pharmaceuticals reflect changes in processes at the cellular and subcellular levels. Due to their growth and cellular characteristics, plant cell suspension cultures can be a suitable model for assessing toxicity. In this study, 10-1000 µg/L of the non-steroidal anti-inflammatory drug diclofenac (DCF) decreased the viability of Nicotiana tabacum BY-2 cells after 24 h of treatment. Further, 0.1-10 mg/L DCF diminished the density of the cell suspension by 9-46% after 96 h of treatment, but at 1 and 10 µg/L, DCF increased the density by 13% and 5%, respectively, after 120 h. These changes were accompanied by increased production of total reactive oxygen species (ROS) and mitochondrial superoxide (up to 17-fold and 5-fold, respectively), and a decrease in the mitochondrial membrane potential (by ∼64%) especially at 1000 µg/L DCF. The increased ROS production was accompanied by decrease in level of reactive nitrogen species (RNS; by 36%) and total thiols (by 61%). Damage to BY-2 cells was evidenced by accumulation of neutral red in acidic compartments (up to 10-fold at 1000 µg/L DCF), and increase of autophagic vacuole formation (up to 8-fold at 1000 µg/L DCF). Furthermore, irregular or stretched nuclei were observed in nearly 27% and 50% of cells at 100 and 1000 µg/L DCF, respectively. Highest levels of chromatin condensation (11% of cells) and apoptotic DNA fragmentation (7%) were found at 10 µg/L DCF. The results revealed a significant effect of DCF on BY-2 cells after 24 h of exposure. Changes in the growth and viability parameters were indisputably related to ROS and RNS production, changes in mitochondrial function, and possible activation of processes leading to cell death.

Diclofenac as an environmental threat: Impact on the photosynthetic processes of Lemna minor chloroplasts.

Mechanisms of pharmaceuticals action on biochemical and physiological processes in plants that determine plant growth and development are still mostly unknown. This study deals with the effects of non-steroidal anti-inflammatory drug diclofenac (DCF) on photosynthesis as an essential anabolic process. Changes in primary and secondary photosynthetic processes were assessed in chloroplasts isolated from Lemna minor exposed to 1, 10, 100, and 1000 µM DCF. Decreases in the potential and effective quantum yields of photosystem II (FV/FM by 21%, ΦII by 44% compared to control), changes in non-photochemical fluorescence quenching (NPQ), and a substantial drop in Hill reaction activity (by 73%), especially under 1000 µM DCF, were found. Limitation of electron transport through photosystem II was confirmed by increased fluorescence signals in steps J and I (by 50% and 23%, respectively, under 1000 µM DCF) in OJIP fluorescence transient. Photosystem I exhibited changes only in the redox state of P700 reaction centres (decrease in Pm by 10%, increase in reduced P700 by 5% under 1000 µM DCF). Similarly, RuBisCO activity was only lowered by 30% under 1000 µM DCF. In contrast, a significant increase in reactive oxygen and nitrogen species (by 116% and 157%, respectively) was observed under 10 µM DCF, and lipid peroxidation increased even at 1 µM DCF (by nearly seven times compared to the control). Results demonstrate the ability of environmentally relevant DCF concentrations to induce oxidative stress in isolated duckweed chloroplasts; however, photosynthetic processes were affected considerably only by the highest DCF treatments.

Sensitivity of physiological and biochemical endpoints in early ontogenetic stages of crops under diclofenac and paracetamol treatments.

Early stages of ontogenesis determining subsequent growth, development, and productivity of crops can be affected by wastewater and sludge contaminated with pharmaceuticals. Diclofenac (DCF) and paracetamol (PCT; both 0.0001 to 10 mg/L) did not affect seed germination and primary root length of onion, lettuce, pea, and tomato. Conversely, 20-day-old pea and maize plants exhibited decrease in biomass production, leaf area (by approx. 40% in pea and 70% in maize under 10 mg/L DCF), or content of photosynthetic pigments (by 10% and 60% under 10 mg/L PCT). Quantum yields of photosystem II were reduced only in maize (FV/FM and ΦII by more than 40% under 10 mg/L of both pharmaceuticals). Contents of H2O2 and superoxide increased in roots of both species (more than four times under 10 mg/L PCT in pea). Activities of antioxidant enzymes were elevated in pea under DCF treatments, but decreased in maize under both pharmaceuticals. Oxidative injury of root cells expressed as lowered oxidoreductase activity (MTT assay, by 40% in pea and 80% in maize) and increase in malondialdehyde content (by 60% and 100%) together with the membrane integrity disruption (higher Evans Blue accumulation, by 100% in pea and 300% in maize) confirmed higher sensitivity of maize as a C4 monocot plant to both pharmaceuticals.

Possible ecological risk of two pharmaceuticals diclofenac and paracetamol demonstrated on a model plant Lemna minor.

Lemna minor is often used in environmental risk assessment and it can be supposed that usually evaluated parameters will be reliable even for assessing the risk of pharmaceuticals. Subtle changes in duckweed plant number, biomass production, and leaf area size induced by 10-day-exposure to diclofenac (DCF) and paracetamol (PCT) (0.1, 10, and 100 µg/L), excepting 100 µg/L DCF, are in contrast with considerable changes on biochemical and histochemical level. Both drugs caused a decrease in content of photosynthetic pigments (by up to 50%), an increase in non-photochemical quenching (by 65%) and decrease in relative chlorophyll fluorescence decay values (by up to 90% with DCF). Both DCF and especially PCT increased amount of reactive nitrogen and oxygen species in roots. DCF-induced effects included mainly increased lipid peroxidation (by 78%), disturbation in membrane integrity and lowering both oxidoreductase and dehydrogenase activities (by 30%). PCT increased the content of soluble proteins and phenolics. Higher concentrations of both DCF and PCT increased the levels of oxidised ascorbate (by 30%) and oxidised thiols (by up to 84% with DCF). Glutathion-reductase activity was elevated by both pharmaceuticals (nearly by 90%), glutathion-S-transferase activity increased mainly with PCT (by 22%). The early and sensitive indicators of DCF and PCT phytotoxicity stress in duckweed are mainly the changes in biochemical processes, connected with activation of defense mechanisms against oxidative stress.

Root and foliar uptake, translocation, and distribution of [14C] fluoranthene in pea plants (Pisum sativum).

Uptake of (14)C-labeled fluoranthene ([(14)C]FLT) via both roots and leaves of Pisum sativum seedlings and distribution of [(14) C] in plants by both acropetal and basipetal transport was evaluated. The highest [(14)C] level was found in the root base (≈270 × 10(4) dpm/g dry wt) and the lowest level in the stem apex (<2 × 10(4) dpm/g dry wt) after just 2 h of root exposure. For foliar uptake, the highest level of [(14)C] was found in the stem and root apex (both ≈2 × 10(4) dpm/g dry wt) (except for treated leaves), while the lowest level was found in the root base (<0.6 × 10(4) dpm/g dry wt).

Evaluation of antibacterial properties of novel phthalocyanines against Escherichia coli--comparison of analytical methods.

We analyzed antibacterial effects of several novel phthalocyanines against Escherichia coli and evaluated the suitability of flow cytometry for the detection of antibacterial effects of phthalocyanines in comparison with routinely used cultivation. After 3h of exposure under cool white light eight cationic phthalocyanines showed very high antibacterial activity in the concentration of 2.00 mg L(-1) and four of them were even efficient in the concentration of 0.20 mg L(-1). Antibacterial activity of neutral and anionic compounds was considerably lower or even negligible. No antibacterial effect was detected when bacteria were exposed without illumination. Binding affinity to bacterial cells was found to represent an important parameter influencing phthalocyanine antibacterial activity that can be modified by total charge of peripheral substituents and by the presence of suitable functional groups inside them. Agglomeration of cells observed in suspensions treated with a higher concentration of certain cationic phthalocyanines (the strongest binders to bacterial membrane) affected cytometric measurements of total cell counts, thus without appropriate pretreatment of the sample before analysis this parameter seems not to be fully valid in the evaluation of phthalocyanine antibacterial activity. Cytometric measurement of cell membrane integrity appears to be a suitable and even more sensitive parameter than cultivation.

Lemna minor exposed to fluoranthene: growth, biochemical, physiological and histochemical changes.

Polycyclic aromatic hydrocarbons (PAHs) represent one of the major groups of organic contaminants in the aquatic environment. Duckweed (Lemna minor L.) is a common aquatic plant widely used in phytotoxicity tests for xenobiotic substances. The goal of this study was to assess the growth and the physiological, biochemical and histochemical changes in duckweed exposed for 4 and 10 days to fluoranthene (FLT, 0.1 and 1 mgL(-1)). Nonsignificant changes in number of plants, biomass production, leaf area size, content of chlorophylls a and b and carotenoids and parameters of chlorophyll fluorescence recorded after 4 and 10 days of exposure to FLT were in contrast with considerable changes at biochemical and histochemical levels. Higher occurrence of reactive oxygen species (ROS) caused by an exposure to FLT after 10 days as compared to control (hydrogen peroxide elevated by 13% in the 0.1 mgL(-1) and by 41% in the 1 mgL(-1) FLT; superoxide anion radical by 52% and 115% respectively) reflected in an increase in the activities of antioxidant enzymes (superoxide dismutase by 3% in both treatments, catalase by 9% and 1% respectively, ascorbate peroxidase by 21% and 5% respectively, guaiacol peroxidase by 12% in the 0.1 mgL(-1) FLT). Even the content of antioxidant compounds like ascorbate (by 20% in the 1 mgL(-1) FLT) or total thiols (reduced forms by 15% in the 0.1 mgL(-1) and 8% in the 1 mgL(-1) FLT, oxidized forms by 36% in the 0.1 mgL(-1) FLT) increased. Increased amount of ROS was followed by an increase in malondialdehyde content (by 33% in the 0.1 mgL(-1) and 79% in the 1 mgL(-1) FLT). Whereas in plants treated by the 0.1 mgL(-1) FLT the contents of total proteins and phenols increased by 15% and 25%, respectively, the 1 mgL(-1) FLT caused decrease of their contents by 32% and 7%. Microscopic observations of duckweed roots also confirmed the presence of ROS and related histochemical changes at the cellular and tissue levels. The assessment of phytotoxicity of organic pollutant in duckweed based only on the evaluation of growth parameters could not fully cover the irreversible changes already running at the level of biochemical processes.

Root response in Pisum sativum and Zea mays under fluoranthene stress: morphological and anatomical traits.

Introduced organic pollutants in all ecosystem compartments can cause stress resulting in a wide range of responses including different root development. In this study, the effects of a polycyclic aromatic hydrocarbon-fluoranthene (FLT; 0.1, 1 and 7 mg L(-1)) on the growth, morphology and anatomical structure of roots of pea and maize was evaluated. In comparison with pea, significant stimulation of root system growth of maize caused by 0.1 mg L(-1) (total length longer by 25%, number of lateral roots by 35%) and its reduction (total length by 34%) already by 1 mg L(-1) FLT is the proof of different interspecies sensitivity to low and higher environmental loading. Nevertheless in both plant species a high loading 7 mg L(-1) FLT significantly reduced both growth (total length by 95% in pea, 94% in maize) and the number of lateral roots (by 78% in pea, 94% in maize). Significantly increased thickness of root of both maize and pea was caused by 7 mg L(-1) FLT and in maize already by 0.1 mg L(-1) FLT. It may be mainly connected with an enlargement of stele area (up to 50% in pea and 25% in maize). Increased xylem area in root tip (by up to 385% in pea, 167% in maize) and zone of maturation (up to 584% in pea, 70% in maize) and its higher portion in stele area of root tip (by 9% in pea, 21% in maize), mainly in roots exposed 7 mg L(-1) FLT, are a proof of an early differentiation of vascular tissue and a shortening of root elongation zone. Moreover in both plant species exposed to this treatment, the decline of rhizodermis cells and external layers of primary cortex was found and also significant deformation of primordia of lateral roots was recorded.

The use of physiological characteristics for comparison of organic compounds phytotoxicity.

The influence of intact (FLT) and photomodified (phFLT) fluoranthene (0.05, 0.5 and 5 micromol l(-1)) and herbicide Basagran (5, 20, 35 and 50 nmol l(-1)) on the germination, growth of seedlings and photosynthetic processes in pea plants (Pisum sativum L., cv. Garde) was investigated. The germination was significantly inhibited already by the lowest concentration (0.05 micromol l(-1)) of FLT and phFLT, while Basagran caused inhibition only in higher concentrations (35 and 50 nmol l(-1)). The growth of roots was significantly inhibited by higher concentration 5 micromol l(-1) of both FLT and phFLT and the shoot of seedlings was significantly influenced only by photomodified form. The length of root and shoot was inhibited already by concentration 5 nmol l(-1) of Basagran. Organic compounds applied on chloroplasts suspension influenced primary photochemical processes of photosynthesis. In chlorophyll fluorescence parameters, the significant increase of F(0) values and the decrease of F(V)/F(M) and Phi(II) values by application of FLT (0.5 and 5 micromol l(-1)) and phFLT (0.05, 0.5 and 5 micromol l(-1)) was recorded. The maximum capacity of PSII (F(V)/F(M)) was influenced by the highest (50 nmol l(-1)) and the effective quantum yield of PSII (Phi(II)) already by the lowest (5 nmol l(-1)) concentration of Basagran. Hill reaction activity decreased and was significantly inhibited by higher concentration (0.5 and 5 micromol l(-1)) of FLT and phFLT and already by the lowest concentration (5 nmol l(-1)) of Basagran.

Evaluation of fluoranthene phytotoxicity in pea plants by Hill reaction and chlorophyll fluorescence.

The effect of both increased concentrations (0.01 and 1 mg l(-1)) of fluoranthene (FLT) and the duration of exposure (18 and 25 days) on the growth and photosynthetic processes in pea plants (Pisum sativum L., cv. Garde) was investigated. FLT concentration in roots and shoot of pea plants was also determined. The obtained results demonstrated that the higher concentration of FLT (1 mg l(-1)) significantly inhibited the growth of the pea plants after 25 days of the application, also affected the content of photosynthetic pigments (chlorophyll a, b and carotenoids), and the primary photochemical processes of photosynthesis. In chlorophyll fluorescence parameters, the significant increase of F(0) values and the decrease of F(V)/F(M) and Phi(II) values was recorded. The Hill reaction of isolated chloroplasts of pea plants was significantly inhibited after 25 days by presence of FLT (0.01 and 1 mg l(-1)) in nutrient solution, while after 18 days no significant response of Hill reaction activity was recorded. The fluoranthene content in roots and shoot of pea plants increased with increasing FLT concentration in the environment and the substantial accumulation of FLT was observed in the roots.

Inhibitory effect of fluoranthene on photosynthetic processes in lichens detected by chlorophyll fluorescence.

The effect of increasing concentration (0.01, 1 and 5 mg l(-1)) of fluoranthene (FLT) and the duration of exposure (12, 24, 36, 48 and 60 h) on the chlorophyll fluorescence parameters (F0, F(V)/F(M), Phi II and (F(M) - F(S))/F (S)) of symbiotic algae in thalli of two foliose lichens Lasallia pustulata and Umbilicaria hirsuta was investigated. Also the FLT concentration in thalli of both lichen species and the proportion of symbiotic algae (photobionts) in thalli was studied. The results obtained demonstrated that the applied concentration of FLT (1 and 5 mg l(-1)) affected primary photochemical processes of photosynthesis of algae in both lichen species. The F0 values increased and the F(V)/F(M) and Phi II values decreased. The fluoranthene content in thallus of both lichen species was increased with increasing FLT concentration in the environment. Chlorophyll fluorescence parameters showed different sensitivity to the content of FLT in Lasallia pustulata and Umbilicaria hirsuta, respectively. Higher sensitivity, detected in U. hirsuta, can be related to its diverse anatomical structure (higher portion of symbiotic algae in thalli) and to the different (nearly 2.5 times higher) content of FLT after exposure.