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Desiccation in green algae: mechanisms and aquisition of tolerance
Belza, Václav Cedrik ; Pichrtová, Martina (advisor) ; Němcová, Yvonne (referee)
This thesis summarizes the current knowledge of the mechanisms that allow green algae to tolerate even severe desiccation. It provides a comprehensive overview, ranging from the definition of desiccation stress and its impacts on algal cells, through mechanisms that algae employ in defense, to the evolutionary background as well as a synthesis of recent research on the acquisition of desiccation tolerance and factors conditioning it. The first chapter defines the desiccation stress itself and breaks down the processes by which it can damage algal cells, including both morphological and physiological effects. The second chapter discusses diverse mechanisms involved in protection against desiccation. From mechanisms aimed at prevention of water loss (e.g. mucilage production or modification of cell wall permeability), through mechanisms that cause desiccation tolerance (e.g. accumulation of antioxidants, stabilization of proteins and phospholipids etc.), to the formation of resilient life stages. The third chapter is devoted to the evolutionary-historical background behind the emergence of desiccation tolerance per se and overview in which algal groups it is observable today. The last section is a synthesis of modern knowledge regarding acquisition of desiccation tolerance during algal life and...
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Influence of total leaf nitrogen and non-structural carbohydrates on Rubisco content and its activity under ambient and elevated concentrations of carbon dioxide
Vičíková, Magda ; Babák, Libor (referee) ; Hrstka, Miroslav (advisor)
This diploma thesis examines influence of content of leaf nitrogen and non-structural carbohydrates on Rubisco activity and its content under impact of ambient (A = 385 µmolCO2 mol-1) and elevated (E = 700 µmolCO2 mol-1) concentrations of carbon dioxide in needles of Norway spruce (Picea abies L.). The Rubisco activity was determined spectrophotometrically, the Rubisco content by using SDS-PAGE, the content of non-structural carbohydrates by using the anthron method and total leaf nitrogen was determined by using the Kjeldahl method. The Rubisco activity in needles of Norway spruce did not show acclimation on elevated concentration of carbon dioxide, but the activity was elevated concentration of carbon dioxide stimulated during the growing season. The acclimation was proved by Rubisco content, its content was significantly lower in needles cultivated under elevated carbon dioxide. Content of total leaf nitrogen was statistically significantly lower in needles of Norway spruce cultivated under elevated carbon dioxide then in needles cultivated under ambient concentration of carbon dioxide. On the contrary, the content of non-structural carbohydrates was significantly higher in needles cultivated under elevated concentration of carbon dioxide then in variant A. Seasonal changes of Rubisco content depended on content of non-structural carbohydrates, the Rubisco content decreased with increasing content of non-structural carbohydrates. No dependence was detected between seasonal changes of the total leaf content and the Rubisco content.
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Influence of elevated carbon dioxide concentration at Rubisco activity and its content in sunny and shaded needles of Norway spruce
Šibravová, Lenka ; Zemanová, Jana (referee) ; Hrstka, Miroslav (advisor)
Diploma thesis’s aim was to determine Rubisco activity and its content in sunny and shaded needles of Norway spruce (Picea abies [L.] Karst.) and confirm or refuse acclimation on Rubisco enzyme level. Samples were taken on the Experimental ecology station Czech Academy of Sciences at Bílý Kříž (Beskydy Mountains) where needles were cultivated in two cultivation spheres with different concetrations CO2. One cultivation sphere contains atmosphere with ambient (A) concentration CO2 (350 mol CO2 mol-1) and the other contains atmosphere with elevated (E) concentration CO2 (700 mol CO2 mol-1). Rubisco activities were determinated spectrophotometric, Rubisco content was determined by SDS-PAGE method. Samples were taken in the modele of June and in the end of September. Elevated concetration CO2 did not have significant influence on Rubisco activity. Whereas different exposition had significant influence on Rubisco activity in June, when was found lower Rubisco activity in shaded needles than in sunny needles. In September were not find significant differences in Rubisco activity beetwen sunny and shaded needles. We did not find statistically significant differences in Rubisco content between A and E needles in June. Incontrary, we found about 34 % lower Rubisco content in E needles than in A needles, which confirms acclimation on Rubisco enzyme level. In September Rubisco content was several time higher than in June, which evidences the long term building photosynthetic apparatus in coniferous trees.
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Influence of elevated carbon dioxide concentration at Rubisco activity and its content in sunny and shaded leaves of beech
Vičíková, Magda ; Vitoulová, Eva (referee) ; Hrstka, Miroslav (advisor)
This bachelor thesis focuses on influence of elevated carbon dioxide concentration at Rubisco activity and its content in sunny and shaded leaves of beech (Fagus sylvatica). The initial and total activities were measured spectrophotometrically, the content of Rubisco was determined by using SDS-PAGE method. It was observed statistically significant higher activity of Rubisco in leaves cultivated under elevated concentrations of carbon dioxide in June but not in September. In contrary, exposure of leaves (sunny/shaded) did not have significant influence on Rubisco activity in June, but in September was found lower activity of Rubisco in shaded leaves than in sunny leaves. The content of Rubisco was lower in leaves cultivated under elevated concentrations of carbon dioxide (acclimation), with the exception of shaded leaves in September. There was found significantly lower Rubisco content in shaded leaves than in sunny leaves both in June and in September.
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Structure and function of chloroplasts in selected woody plants grown under increased CO2 concentration
Hlízová, Eliška ; Albrechtová, Jana (advisor) ; Kutík, Jaromír (referee)
The effect of elevated CO2 concentration (EC CO2) on photosynthesis has been observed on many hierarchical levels. There was a significant increase in the rate of photosynthesis of examined trees observed in previous studies thus I hypothesised these changes are accompanied by changes of chloroplast ultrastructure and photosystem content and function and the main aim of this study is to evaluate these adjustments. In this study 13 - 14 years old seedlings of Norway spruce (Picea abies L. Karst.) grown in glass domes with adjustable windows - one with ambient CO2 concentration as a control, the other one with simulated EC CO2 (700 ppm) - during the vegetative season were examined. Pigment content, fluorescence and reflectance indexes, activity of photosystem 1 (PS1) and 2 (PS 2) of isolated chloroplasts, size of cross-sectional area of chloroplast and proportion of stromal to granal thylakoids under EC CO2 treatment were investigated. Although there was a significant increase in the maximum rate of photosynthetic assimilation of trees from EC CO2 (observed by other researchers of our team), decreased chlorophyll and carotenoid content as well as the activity of both photosystems were observed, which is usually atributed to photosynthetic acclimation. As the rate of decrease of photosystem 1 and photosystem 2...
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Oxidative stress level as a marker of stress memory in selected genotypes of potato Solanum tuberosum ssp. tuberosum and ssp. andigena
Lotová, Gabriela ; Mašková, Petra (advisor) ; Lhotáková, Zuzana (referee)
Plants are exposed to the stress of the environment throughout their entire live. They therefore had to develop sophisticated mechanisms to avoid or tolerate stress. In some plants, repeated exposure to stress increases tolerance, which is known as stress memory. The aim of this study is to assess stress memory in terms of oxidative stress level. Content of malondialdehyde (MDA), reactive oxygen species (ROS) and the electrolyte leakage were chosen as markers of oxidative stress. Fresh weight, plant height and water content were also evaluated. The level of oxidative stress was assessed in several genotypes of Solanum tuberosum subspecies, Andigena and Tuberosum. In vitro culture did not work well for the evaluation of stress memory, ex vitro partially did. The content of MDA in 66B was significantly lower than in cv. Lada (Tuberosum) in root (in vitro) and shoot (ex vitro) in control groups as well as during water shortage. Treatment of acclimation-inducing cold before the stress-inducing cold had a variable effect on growth and electrolyte leakage according to the culture conditions. In vitro, the effect on electrolyte leakage in roots of cv. Lada was positive, in leaves of 66B (Andigena) it was negative. In ex vitro, a positive effect was found on electrolyte leakage in 66B leaves, but at the...
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Structure and function of chloroplasts in selected woody plants grown under increased CO2 concentration
Hlízová, Eliška ; Albrechtová, Jana (advisor) ; Kutík, Jaromír (referee)
The effect of elevated CO2 concentration (EC CO2) on photosynthesis has been observed on many hierarchical levels. There was a significant increase in the rate of photosynthesis of examined trees observed in previous studies thus I hypothesised these changes are accompanied by changes of chloroplast ultrastructure and photosystem content and function and the main aim of this study is to evaluate these adjustments. In this study 13 - 14 years old seedlings of Norway spruce (Picea abies L. Karst.) grown in glass domes with adjustable windows - one with ambient CO2 concentration as a control, the other one with simulated EC CO2 (700 ppm) - during the vegetative season were examined. Pigment content, fluorescence and reflectance indexes, activity of photosystem 1 (PS1) and 2 (PS 2) of isolated chloroplasts, size of cross-sectional area of chloroplast and proportion of stromal to granal thylakoids under EC CO2 treatment were investigated. Although there was a significant increase in the maximum rate of photosynthetic assimilation of trees from EC CO2 (observed by other researchers of our team), decreased chlorophyll and carotenoid content as well as the activity of both photosystems were observed, which is usually atributed to photosynthetic acclimation. As the rate of decrease of photosystem 1 and photosystem 2...
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Influence of total leaf nitrogen and non-structural carbohydrates on Rubisco content and its activity under ambient and elevated concentrations of carbon dioxide
Vičíková, Magda ; Babák, Libor (referee) ; Hrstka, Miroslav (advisor)
This diploma thesis examines influence of content of leaf nitrogen and non-structural carbohydrates on Rubisco activity and its content under impact of ambient (A = 385 µmolCO2 mol-1) and elevated (E = 700 µmolCO2 mol-1) concentrations of carbon dioxide in needles of Norway spruce (Picea abies L.). The Rubisco activity was determined spectrophotometrically, the Rubisco content by using SDS-PAGE, the content of non-structural carbohydrates by using the anthron method and total leaf nitrogen was determined by using the Kjeldahl method. The Rubisco activity in needles of Norway spruce did not show acclimation on elevated concentration of carbon dioxide, but the activity was elevated concentration of carbon dioxide stimulated during the growing season. The acclimation was proved by Rubisco content, its content was significantly lower in needles cultivated under elevated carbon dioxide. Content of total leaf nitrogen was statistically significantly lower in needles of Norway spruce cultivated under elevated carbon dioxide then in needles cultivated under ambient concentration of carbon dioxide. On the contrary, the content of non-structural carbohydrates was significantly higher in needles cultivated under elevated concentration of carbon dioxide then in variant A. Seasonal changes of Rubisco content depended on content of non-structural carbohydrates, the Rubisco content decreased with increasing content of non-structural carbohydrates. No dependence was detected between seasonal changes of the total leaf content and the Rubisco content.
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Influence of elevated carbon dioxide concentration at Rubisco activity and its content in sunny and shaded needles of Norway spruce
Šibravová, Lenka ; Zemanová, Jana (referee) ; Hrstka, Miroslav (advisor)
Diploma thesis’s aim was to determine Rubisco activity and its content in sunny and shaded needles of Norway spruce (Picea abies [L.] Karst.) and confirm or refuse acclimation on Rubisco enzyme level. Samples were taken on the Experimental ecology station Czech Academy of Sciences at Bílý Kříž (Beskydy Mountains) where needles were cultivated in two cultivation spheres with different concetrations CO2. One cultivation sphere contains atmosphere with ambient (A) concentration CO2 (350 mol CO2 mol-1) and the other contains atmosphere with elevated (E) concentration CO2 (700 mol CO2 mol-1). Rubisco activities were determinated spectrophotometric, Rubisco content was determined by SDS-PAGE method. Samples were taken in the modele of June and in the end of September. Elevated concetration CO2 did not have significant influence on Rubisco activity. Whereas different exposition had significant influence on Rubisco activity in June, when was found lower Rubisco activity in shaded needles than in sunny needles. In September were not find significant differences in Rubisco activity beetwen sunny and shaded needles. We did not find statistically significant differences in Rubisco content between A and E needles in June. Incontrary, we found about 34 % lower Rubisco content in E needles than in A needles, which confirms acclimation on Rubisco enzyme level. In September Rubisco content was several time higher than in June, which evidences the long term building photosynthetic apparatus in coniferous trees.
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Influence of elevated carbon dioxide concentration at Rubisco activity and its content in sunny and shaded leaves of beech
Vičíková, Magda ; Vitoulová, Eva (referee) ; Hrstka, Miroslav (advisor)
This bachelor thesis focuses on influence of elevated carbon dioxide concentration at Rubisco activity and its content in sunny and shaded leaves of beech (Fagus sylvatica). The initial and total activities were measured spectrophotometrically, the content of Rubisco was determined by using SDS-PAGE method. It was observed statistically significant higher activity of Rubisco in leaves cultivated under elevated concentrations of carbon dioxide in June but not in September. In contrary, exposure of leaves (sunny/shaded) did not have significant influence on Rubisco activity in June, but in September was found lower activity of Rubisco in shaded leaves than in sunny leaves. The content of Rubisco was lower in leaves cultivated under elevated concentrations of carbon dioxide (acclimation), with the exception of shaded leaves in September. There was found significantly lower Rubisco content in shaded leaves than in sunny leaves both in June and in September.
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