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Physiological, structural, and biochemical leaf traits of selected Poaceae species involved in oxidative stress protection and acclimation to different light conditions
Hunt, Lena Macrie ; Albrechtová, Jana (advisor) ; Lux, Alexander (referee) ; Šantrůček, Jiří (referee)
This thesis examines physiological, structural, and biochemical leaf traits in grasses (Poaceae family) and how they contribute to oxidative stress protection. Light is a major factor contributing both to oxidative stress in plants and the induction of protective mechanisms at the leaf level. The agriculturally important species barley (Hordeum vulgare) was used to investigate responses to varying irradiance and atmospheric CO2 levels. Barley was further used as a model organism to study the influence of different spectral qualities on oxidative protective mechanisms, particularly phenolic compound induction. This thesis also examines the protective leaf functional traits of wild grass species (Nardus stricta, Calamagrostis villosa, Molinia caerulea, and Deschampsia cespitosa) in a high-irradiance arctic-alpine tundra grassland. Phenolic compounds are important protective secondary metabolites in plants that protect against oxidative stress from high irradiance. This thesis evaluates phenolic compounds and their contributions to plant stress tolerance and introduces a novel method of quantifying the histochemical detection of phenolics in leaf cross-sections. Key results indicate that light quantity and quality play major influential roles in the accumulation of phenolic compounds. High irradiance...
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Effect of water supply on structure and selected physiological parameters of leaf in woody species.
Horešovská, Michaela ; Lhotáková, Zuzana (advisor) ; Votrubová, Olga (referee)
Woody plants must cope with drought as it is one of the main factors of the ongoing climate change. The ability of woody plants to adapt to this stressor determines whether they will survive in constantly changing environmental conditions. The deciduous trees of European temperate forests are not as adapted to drought as Mediterranean trees and shrubs, and therefore the lack of water is a major stress for them. Leaf turned out to be the most flexible plant organ in its response to drought. The aim of this work is to summarize the knowledge about the effect of water deficit on the anatomical structure of leaf and its selected physiological parameters. The first part of this thesis is focused on the drought affecting European tree species and their various defensive strategies against this factor. It mainly describes the modification of leaf's anatomy structure as their defensive reactions observed in dermal, ground and vascular tissue. The second part of this thesis is devoted to the influence of water deficit on the selected leaf's physiological processes, especially on transpiration and photosynthesis, and the key role of stomata closure on both of these physiological processes. Drought causes changes in leaf anatomical structure and its physiological functions. The leaf's developmental stage at...
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Anatomical study of shade and sun European beech leaf under elevated CO2.
Horská, Jana ; Lhotáková, Zuzana (advisor) ; Urban, Otmar (referee)
The present Master thesis focuses on evalution of CO2 concentration and irradiance on selected leaf anatomical parameters of European Beech (Common Beech) Fagus sylvatica L.. The process of photosynthesis is remarkably determined by numerous extrenal factors, among them by atmoshperic CO2 concentration and irradiance and is closely correlated with leaf anatomical parameters. One of these most important anatomical parameters affecting the net assimilation rate is an internal leaf surface, which corresponds to mesophyll area avialable for gas exhcange. Experimental material of the study was sampled from the leaves of juvenile trees of F. sylvatica planted in 2005 and growing under ambient (390 ppm, AC) and elevated (700 ppm, EC) CO2 concentrations on the experimental site of the Global Change Research Center AS CR at Bílý Kříž in the Beskydy Mountains. Sun and shade leaves were sampled from trees of both CO2 treatments in two seasons 3 years apart (2009 and 2012). To determine leaf anatomical parameters, the stereological methods were applied, which yield unbiased estimation of measured parameters, particularly the Fakir method for internal leaf surface determination. The EC effect was observed on the leaves sampled in 2009 only in the decrease of proportion of intercellular spaces in mesophyll. In...
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Effect of water supply on structure and selected physiological parameters of leaf in woody species.
Horešovská, Michaela ; Lhotáková, Zuzana (advisor) ; Votrubová, Olga (referee)
Woody plants must cope with drought as it is one of the main factors of the ongoing climate change. The ability of woody plants to adapt to this stressor determines whether they will survive in constantly changing environmental conditions. The deciduous trees of European temperate forests are not as adapted to drought as Mediterranean trees and shrubs, and therefore the lack of water is a major stress for them. Leaf turned out to be the most flexible plant organ in its response to drought. The aim of this work is to summarize the knowledge about the effect of water deficit on the anatomical structure of leaf and its selected physiological parameters. The first part of this thesis is focused on the drought affecting European tree species and their various defensive strategies against this factor. It mainly describes the modification of leaf's anatomy structure as their defensive reactions observed in dermal, ground and vascular tissue. The second part of this thesis is devoted to the influence of water deficit on the selected leaf's physiological processes, especially on transpiration and photosynthesis, and the key role of stomata closure on both of these physiological processes. Drought causes changes in leaf anatomical structure and its physiological functions. The leaf's developmental stage at...
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How does the leaf structure determine the leaf optical properties.
Peychlová, Anna ; Lhotáková, Zuzana (advisor) ; Tylová, Edita (referee)
An internal leaf structure determines the way the light passes through the leaf and, thus, in this way it affects the use of the light in photosynthesis. The light reaching the leaf can be reflected, absorbed or transmitted. Leaf reflectance properties depend on the wavelength of irradiation and on the physical, structural and chemical properties of a leaf. Thereinafter, this Bachelor thesis briefly describes spectral methods used to study leaf optical properties. Furthermore, the thesis focuses on leaf anatomical structures and their effect on leaf optical properties, mainly in visible region of electromagnetic radiation (400-700 nm) and in near- infra-red region (700-2300 nm). The emphasis is given to the following anatomical properties and structures: epidermis, cuticle, trichomes, mesophyll structure, leaf thickness, chloroplast movement, chlorophyll content and distribution. The aim of the thesis is to summarize current knowledgeon this topic. Key words: leaf anatomy, leaf optical properties, reflectance, intercellular spaces, radiative transfer
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Anatomical study of shade and sun European beech leaf under elevated CO2.
Horská, Jana ; Lhotáková, Zuzana (advisor) ; Urban, Otmar (referee)
The present Master thesis focuses on evalution of CO2 concentration and irradiance on selected leaf anatomical parameters of European Beech (Common Beech) Fagus sylvatica L.. The process of photosynthesis is remarkably determined by numerous extrenal factors, among them by atmoshperic CO2 concentration and irradiance and is closely correlated with leaf anatomical parameters. One of these most important anatomical parameters affecting the net assimilation rate is an internal leaf surface, which corresponds to mesophyll area avialable for gas exhcange. Experimental material of the study was sampled from the leaves of juvenile trees of F. sylvatica planted in 2005 and growing under ambient (390 ppm, AC) and elevated (700 ppm, EC) CO2 concentrations on the experimental site of the Global Change Research Center AS CR at Bílý Kříž in the Beskydy Mountains. Sun and shade leaves were sampled from trees of both CO2 treatments in two seasons 3 years apart (2009 and 2012). To determine leaf anatomical parameters, the stereological methods were applied, which yield unbiased estimation of measured parameters, particularly the Fakir method for internal leaf surface determination. The EC effect was observed on the leaves sampled in 2009 only in the decrease of proportion of intercellular spaces in mesophyll. In...
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Mesophyll CO2 conductance in consequence with the leaf anatomy and environmental factors.
Malcová, Kateřina ; Lhotáková, Zuzana (advisor) ; Nátr, Lubomír (referee)
The CO2 diffusion pathway from the atmosphere surrounding the leaf to the chloroplast stroma is composed of several parts, where each part poses certain resistance to the CO2 flux. The CO2 diffusion from the sub-stomatal cavities to the stroma is limited due to mesophyll conductance (gm), which includes CO2 movement in gas, liquid and lipid phases. The mesophyll conductance is influenced by factors that are both internal (e.g. leaf anatomy and leaf age) and external (e.g. irradiance, temperature). Internal factors exhibit rather long-term responses of gm, while external factors are involved in short-term changes. For these rapid changes are probably responsible aquaporins. gm significantly influences the rate of net photosynthesis, almost in the same range as a stomatal conductance does. The limitation of photosynthesis given by mesophyll conductance is not fixed and varies among species and plant functional groups. Due to continual increase of CO2 concentration in the atmosphere, variability in gm can lead to enhanced competitive potencial of some plant species.
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Carbon dioxide transport through the hypostomatous plant leaf
NEUWIRTHOVÁ, Jitka
Mesophyll conductance is (together with stomatal conductance) a crucial component of diffusion limitations of photosynthesis and it is important to understand the mechanisms of CO2 fluxes through the leaves. Here I tested a new technique for estimation of drawdown in CO2 concentration across hypostomatous leaves based on carbon isotope composition (13C) of leaf cuticle and cuticular waxes isolated from opposite leaf sides.
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