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Leaf structural changes induced by tropospheric ozone.
Češpírová, Zdeňka ; Lhotáková, Zuzana (advisor) ; Hála, Michal (referee)
Tropospheric ozone is an important pollutant formed by the photochemical reactions of ultraviolet radiation and nitrogenous. Recently, its concentration in the air is increasing due to the promoting climate change and antropogenic activities, mainly because of combustion of the fossil fuels. The ozone is highly reactive molecule degrading to the reactive oxygen species having negative effects on the leaf physiological functions and structure. Ozone penetrates the leaf through the stomata, thereafter it reacts with the cells and their singular compartments. The products formed due to ozone degradation are able to cause the disintegration of plasma membranes and other oxidative damage, for example accumulation of plastoglobuli inside the chloroplasts, changes in the shape of chloroplasts, mitochondria or peroxisomes. At the macroscopic level the visible lesions, chloroses and necroses are observed. In addition, the faster senescence of leaves is observed under the effect of ozone. The main aim of present thesis is to review knowledge of the ozone-induced changes in the leaf structure beginning on the cell structure level and ending at the whole plant body level and to explain physiological mechanisms leading to these damages. Key words: ozone, oxidative stress, leaf structure, mesophyll, reactive...
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Changes in anatomy of coniferous needles in response to anthropogenic pollution
Štěpánová, Kristýna ; Albrechtová, Jana (advisor) ; Votrubová, Olga (referee)
The anatomical structure of conifer needles is affected by external enviromental conditions. From abiotic factors, apart of irradiation, main determining factors are drought and extreme temperatures belonging to factors of climate change. Anthropogenic pollution has a significant position among the external abiotic factors that cause changes in the structure of needles. At present, the main polluting compounds are tropospheric ozone, SO2, NOx and PM. Due to the effect of atmospheric pollutants, the proportion of individual tissues in the needle changes, so does the proportion of intercellular spaces and the internal structure of cellular organelles, especially chloroplasts. Mesophyll cells show signs of degradation, especially around the substomatal cavity. There appears a visible damage on the needle surface - chloroses and necroses. The process of senescence speeds up during the activity of stress enviromental factors, such as anthropogenic pollution. The main objective of the present Thesis is to gather knowledge about changes of conifer needle structure, caused by anthropogenic pollution, especially ozone, SO2 and NOx, in combination with climate change factors - drought and extreme temperatures. The review is focused on modifications on various anatomic hierarchical levels, from visible...
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Leaf structural changes induced by tropospheric ozone.
Češpírová, Zdeňka ; Lhotáková, Zuzana (advisor) ; Hála, Michal (referee)
Tropospheric ozone is an important pollutant formed by the photochemical reactions of ultraviolet radiation and nitrogenous. Recently, its concentration in the air is increasing due to the promoting climate change and antropogenic activities, mainly because of combustion of the fossil fuels. The ozone is highly reactive molecule degrading to the reactive oxygen species having negative effects on the leaf physiological functions and structure. Ozone penetrates the leaf through the stomata, thereafter it reacts with the cells and their singular compartments. The products formed due to ozone degradation are able to cause the disintegration of plasma membranes and other oxidative damage, for example accumulation of plastoglobuli inside the chloroplasts, changes in the shape of chloroplasts, mitochondria or peroxisomes. At the macroscopic level the visible lesions, chloroses and necroses are observed. In addition, the faster senescence of leaves is observed under the effect of ozone. The main aim of present thesis is to review knowledge of the ozone-induced changes in the leaf structure beginning on the cell structure level and ending at the whole plant body level and to explain physiological mechanisms leading to these damages. Key words: ozone, oxidative stress, leaf structure, mesophyll, reactive...
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The effect of leaf structure on the leaf optical properties - Implication for water regime.
Neuwirthová, Eva ; Albrechtová, Jana (advisor) ; Rothová, Olga (referee)
Due to coal mining activities, heap substrates rich in clays with poor water permeability and lack of nutrients are relocated outside of mines representing hostile environment to the majority of vegetation. A material from the surface coal mines in Sokolov forming the Velká Podkrušnohorská Heap (VPS) form large locality showing characteristics of anthropogenically devasted landscape. The aim of the present study was to compare leaf structural and biochemical parameters with relation to a leaf reflectance of two pioneer tree species Salix caprea and Populus tremula with regard to leaf water regime and leaf adaptation to a water loss. From the methodological point of view, the study aimed on contribution to determine relation of selected leaf structural parameters to leaf reflectance what has not been intensively studied yet. The foliage of trees P. tremula and S. caprea grown on succession localities S2 a S3 for 30 years was used as a material for my study. The material was studied for its structure using the leaf cross sections nd abaxial epidermal strips (thickness of the leaf tissue layers and of a leaf, stomatal size density and area). Other studied parameters were contents of photosynthetic pigments, specific leaf area (SLA), water potential and leaf reflectance in regions of photosyntetically...
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