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Arsenic toxicity and hyperaccumulation in plants and their potentail use in phytoremediation
Gímeš, Lukáš ; Mašková, Petra (advisor) ; Podlipná, Radka (referee)
Arsenic is classified as a heavy metalloid. Small amounts of arsenic can be found in the environment naturally, but human activity constantly increases the amount of arsenic in the soil. Increasing arsenic contamination of the soil causes serious health problems for both animals and humans. Due to its toxicity, it can also cause considerable problems for plants. Arsenic negatively affects a number of processes in the body of plants, such as oxidative stress or the metabolism of important macromolecules. Photosynthesis is a physiological process that is the most affected by arsenic toxicity. Closely related to photosynthesis are the growth properties of plants. Negative effects that arsenic has on many biochemical, physiological and morphological processes in the plant body, we must understand the uptake, translocation and detoxification of arsenic in the plant body. Arsenic hyperaccumulators are plants that can accumulate orders of magnitude higher concentrations of As and better manage the phytotoxicity of this contaminant than non-hyperaccumulating plants. Hyperaccumulation of heavy metals is associated with changes in the physiological properties of plants. A common characteristic of hyperaccumulators is that they can accumulate the higher concentrations of metals they in the aboveground parts...
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Uptake and metabolism of 137Cs in plants
Šustr, Marek ; Tylová, Edita (advisor) ; Maršík, Petr (referee)
Plants are able to uptake radiocesium from soil, which is the potential route to enter the food chain. Cesium mobility in soil is determined by clay particles. Cesium can be reversibly ad- sorbed on their surface or can be fixed between layers. Mineral illit has the highest selectivity for cesium due to its frayed edges. Organic matter determines cesium mobility only in soil with organic matter content above 90 %. Cesium is more available for plants in this soil. Cesium uptake varies among species. Many plant species accumulating big amounts of cesium belong to family Chenopodiaceae. Cesium uptake is affected by other cations in soil solution. Potassium is the most effective one. Increasing of external potassium concentration from 50 μM to 250 μM decreased cesium uptake thirty-fold. Potassium affects cesium mobili- ty in soil and plant uptake. Due to chemical similarities of cesium and potassium some potassium transporters efficiently transport both cations. Potassium transporters are therefore considered the main entrance site in plant roots. Great contribution to cesium uptake is dedi- cated to high-affinity potassium transporter HAK5. Another great part of cesium uptake is mediated by non-selective cation channels. Plants can uptake up to 80 % of cesium applied on shoot surface. Cesium is highly...
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Uptake and Bioavailability of Copper after Liming of Alder Plantation
Jakl, M. ; Kuneš, I. ; Jaklová Dytrtová, Jana ; Balaš, M. ; Tlustoš, P.
The availability of copper in mountain forest soil (7 years after fertilization) afforested with alder (Alnus incana (L.) Moench) was explored using the diffusive gradient in thin films (DGT) technique compared with its water soluble fraction in soil and its total content in plant compartments. DGT seems to be more promising method determining elements availability; it corresponds with total concentrations in alder tissues closely than contents in water extract. Fertilization increased concentration of Cu in the thinnest root fraction; its total amounts in other tissues of fertilized alders were significantly higher than in the control.
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