Lemna
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Vibrio cholerae (Vc) has been isolated from roots of aquatic plants during epidemic or interepidemic periods. It has been suggested that the lectins from the roots of aquatic plants play a role as reservoirs of Vc. In this paper, we evaluated the activity of lectins from Lemna minor and Eichornia crassipens plants as potential mediators of the Vc strain El Tor (Vct). We found that Lemna minor extract showed high specificity towards blood groups O and B. Eichornia crassipens extract showed high specificity towards blood group A and O. Sugar competition experiments demonstrated that Lemna minor extract showed a high recognition to Neu5Ac (acid N acetyl neuraminic or sialic acid) and GlcNAc (N-acetyl D glucoseamine) in group B; and GlcNAc in group O. Eichornia crassipens, the recognition was that of GalNAc (N-acetyl-D-galactoseamine) and GlcNAc in group O; and Fuc (L-Fucose) and GlcNAc in group A. Lemna minor and Eichornia crassipens protein extracts (p-ext) increased Vct proliferation and protected to the red cells group O against the hemolytic activity of Vct. Both p-exts did not show any statistical significance on agglutination to Vct when compared to the results from phosphate buffer. According to the results, lectins present in roots may be involved in the proliferation and survival of Vct.
- Klíčová slova
- Lemna minor,
- MeSH
- Araceae chemie MeSH
- lektiny * analýza MeSH
- lidé MeSH
- Pontederiaceae chemie MeSH
- Vibrio cholerae * izolace a purifikace MeSH
- Check Tag
- lidé MeSH
Along with cadmium, lead, mercury and other heavy metals, chromium is an important environmental pollutant, mainly concentrated in areas of intense anthropogenic pressure. The effect of potassium dichromate on Lemna minor populations was tested using the growth inhibition test. Cyto-histological and physiological analyses were also conducted to aid in understanding the strategies used by plants during exposure to chromium. Treatment with potassium dichromate caused a reduction in growth rate and frond size in all treated plants and especially at the highest concentrations. At these concentrations the photosynthetic pathway was also altered as shown by the decrease of maximum quantum yield of photosystem II and the chlorophyll b content and by the chloroplast ultrastructural modifications. Starch storage was also investigated by microscopic observations. It was the highest at the high concentrations of the pollutant. The data suggested a correlation between starch storage and reduced growth; there was greater inhibition of plant growth than inhibition of photosynthesis, resulting in a surplus of carbohydrates that may be stored as starch. The investigation helps to understand the mechanism related to heavy metal tolerance of Lemna minor and supplies information about the behavior of this species widely used as a biomarker.
- MeSH
- Araceae * účinky léků fyziologie ultrastruktura MeSH
- chlorofyl biosyntéza MeSH
- chrom metabolismus toxicita MeSH
- fotosyntéza účinky léků MeSH
- látky znečišťující životní prostředí metabolismus toxicita MeSH
- listy rostlin účinky léků fyziologie ultrastruktura MeSH
- škrob biosyntéza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
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.
- MeSH
- Araceae účinky léků růst a vývoj MeSH
- biologické pigmenty metabolismus MeSH
- biomasa MeSH
- časové faktory MeSH
- chemické látky znečišťující vodu toxicita MeSH
- fluoreny analýza toxicita MeSH
- peroxidace lipidů účinky léků MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Phthalocyanines are prospective chemicals that have applications in industry, medicine and biology due especially to their architectural flexibility and production of reactive oxygen species. Although they are used in so many areas of human activities nowadays, there is still little knowledge of their ecotoxicity. Here we present the first observation of their toxic effects on representatives of the aquatic plants Lemna minor. The tested phthalocyanines possess a wide spectrum of phytotoxicity ranging from seldom (>50 mg L(-1)) to highly toxic 0.11 mg L(-1). Moreover, the potential of phthalocyanines to be used as selective cyanocides or herbicides is discussed as well.
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.
- MeSH
- Araceae účinky léků růst a vývoj ultrastruktura MeSH
- chloroplasty účinky léků metabolismus MeSH
- diklofenak farmakologie toxicita MeSH
- fotosyntéza účinky léků MeSH
- fotosystém I (proteinový komplex) MeSH
- fotosystém II (proteinový komplex) účinky léků metabolismus MeSH
- oxidační stres účinky léků MeSH
- peroxidace lipidů účinky léků MeSH
- transport elektronů účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
Usage of atrazine, a widely used herbicide, is now banned in many countries. Although forbidden to use, significant concentration of this herbicide is still present in the environment. The study focused not only on the toxicity of atrazine itself but also on products of homogeneous photocatalytic degradation. Such degradation was very fast in given conditions (sufficient amount of Fe(III) in the reaction system)-more than 95% of the initial amount of atrazine was eliminated after 30 min of irradiation. The toxicity of atrazine and its photodegradation products were examined on the aquatic plant Lemna minor and microcrustacean Daphnia magna in both acute and chronic tests. While the growth inhibition assay of atrazine for Lemna minor revealed EC50 value of 128.4 μg dm-3, the herbicide did not affect Daphnia in the acute toxicity assay. A degradation product, desethyl-atrazine, has been demonstrated to have a pronounced negative effect on the plant growth. Both atrazine and desethyl-atrazine affect negatively the number of juveniles and number of clutches of Daphnia magna in the chronic toxicity assay. Photocatalytic degradation lowers the negative effect of atrazine in Daphnia magna while photodegradation products still negatively affect Lemna growth.
- MeSH
- Araceae účinky léků MeSH
- atrazin chemie metabolismus MeSH
- chemické látky znečišťující vodu farmakologie MeSH
- Daphnia účinky léků MeSH
- herbicidy farmakologie MeSH
- vodní organismy MeSH
- železité sloučeniny farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
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.
- MeSH
- antioxidancia metabolismus MeSH
- biologické markery metabolismus MeSH
- diklofenak metabolismus toxicita MeSH
- fotosyntéza účinky léků MeSH
- fyziologický stres MeSH
- hodnocení rizik MeSH
- Magnoliopsida účinky léků růst a vývoj metabolismus MeSH
- paracetamol metabolismus toxicita MeSH
- peroxidace lipidů účinky léků MeSH
- reaktivní formy dusíku metabolismus MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The purpose of this study was to determine the toxicity of two different sources of cadmium, i.e. CdCl2and Cd-based Quantum Dots (QDs), for freshwater model plant Lemna minor L. Cadmium telluride QDs were capped with two coating ligands: glutathione (GSH) or 3-mercaptopropionic acid (MPA). Growth rate inhibition and final biomass inhibition of L. minor after 168-h exposure were monitored as toxicity endpoints. Dose-response curves for Cd toxicity and EC50168hvalues were statistically evaluated for all sources of Cd to uncover possible differences among the toxicities of tested compounds. Total Cd content and its bioaccumulation factors (BAFs) in L. minor after the exposure period were also determined to distinguish Cd bioaccumulation patterns with respect to different test compounds. Laser-Induced Breakdown Spectroscopy (LIBS) with lateral resolution of 200µm was employed in order to obtain two-dimensional maps of Cd spatial distribution in L. minor fronds. Our results show that GSH- and MPA-capped Cd-based QDs have similar toxicity for L. minor, but are significantly less toxic than CdCl2. However, both sources of Cd lead to similar patterns of Cd bioaccumulation and distribution in L. minor fronds. Our results are in line with previous reports that the main mediators of Cd toxicity and bioaccumulation in aquatic plants are Cd2+ions dissolved from Cd-based QDs.
- MeSH
- adsorpce MeSH
- Araceae účinky léků růst a vývoj metabolismus MeSH
- biomasa MeSH
- chemické látky znečišťující vodu chemie toxicita MeSH
- chlorid kademnatý metabolismus toxicita MeSH
- glutathion chemie MeSH
- kvantové tečky metabolismus toxicita MeSH
- kyselina 3-merkaptopropionová chemie MeSH
- monitorování životního prostředí metody MeSH
- sladká voda chemie MeSH
- sloučeniny kadmia metabolismus toxicita MeSH
- telur metabolismus toxicita MeSH
- teoretické modely MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
