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A possible role of proline in plant stress memory
Ušák, David ; Holá, Dana (advisor) ; Konrádová, Hana (referee)
The previous exposure to abiotic stress such as drought may prime plants, leading to their improved response upon later stress onset. This phenomenon, called plant stress memory, is linked to a plethora of mechanisms exerted on several levels. A complex analysis of proline metabolism in leaves and roots was performed to test the putative role of proline in such response to recurrent stress, represented by two periods of water deficit, interrupted by a period of rewatering during recovery. To provide a better understanding of intraspecific differences in drought stress memory response of plants and its inheritance, maize (Zea mays L.) parental genotypes with differing drought sensitivity and their F1 reciprocal hybrid offspring were chosen as the plant material. The water deficit had a more pronounced effect on proline metabolism in leaves than in roots. The proline content increased in response to drought, which was linked to a higher proline biosynthesis and a lower proline catabolism. Marked differences in proline metabolism among genotypes were observed, confirming the previous findings that recurrent drought response is not conserved even within the same species. However, contrary to the original assumptions on the role of proline in plant stress memory, the statistical analysis showed that...
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Carbon allocation in evergreen and decidious temperate tree species under the elevated concentration CO2 and O3
Neuwirthová, Eva ; Albrechtová, Jana (advisor) ; Konrádová, Hana (referee)
An ongoing increase in atmospheric CO2 concentrations and tropospheric O3 is expected in coming years. These changes are mostly caused by anthropogenic activities and influence remarkably not only plants but the climate on the Earth. Physiological processes in plants determining carbon assimilation and allocation in plant organs are changing in a consequence of variations of these gases in the environment. Tree species represent importatnt C pools and changes in C allocation may effect their sink capability in the global C cycle.Increased CO2 concentration in the atmosphere often leeds to incereased rate of photosynthesis lowered photorespiration what in turn may lead to enhanced C storage in plant biomass. The C storage into sinks is mediated through the assimilation organs, which are disturbed by O3. Ozone is toxic to plants and trees are due to their longevity exposed to ozone influence repeatedly for long term. The response to increased CO2 and O3 concentrations, is the most commonly investigated on two typical representatives of European temperate species: deciduous European beech (Fagus sylvatica L.) and coniferous Norway spruce (Picea abies L. Karst.) The aim of the present review was to summarize the knowledge about the effects of increased concentrations of CO2 and O3 acting separately or in...
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Variability and mechanisms of exodermis differentiation in plant roots
Blascheová, Zuzana ; Tylová, Edita (advisor) ; Konrádová, Hana (referee)
Environmental conditions affect the formation of apoplastic barriers (endodermis and exodermis) in roots. This was shown on many species in many research papers. The exodermal layer is more variable in response to stress conditions than endodermal layer. Cadmium toxicity, as many other stresses, induces faster development of apoplastic barriers. Most of research papers published so far, however characterized only the response of main root to this type of stress factor. Lateral roots, an important part of the root system absorptive surface, are neglected and there is not much information about their response to cadmium stress. The pattern of apoplastic barriers development was therefore analysed in main and also in lateral roots of various size and position on maternal root axis. We found significant differences in response to cadmium stress among these different root types. Then we summed up the differences between these types of roots. Short lateral roots were generally more responsive to cadmium stress, cadmium affected root branching as well as differentiation of apoplastic barriers in lateral roots. These results help us to better understand the response of complex roots system to environmental conditions. In the second part of this work, the role of CASP genes in exodermal development was...
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Possibilities and Utilisation of Objective Personality Tests of the Vienna Tests System for Detection of Individual Risk-Tendency
Konrádová, Hana ; Niederlová, Markéta (advisor) ; Šípek, Jiří (referee)
The theoretical part of this thesis addresses key concepts related to the individual tendency to take risks - it introduces how this trait is embedded in the concept of personality, establishes essential theoretical issues related to risk and risk-tendency, as well as related important terms, research and authors in the field in question. The key issues, too, are methods of risk behaviour detection with emphasis on current trends in psychodiagnostics, thus in the following part the fields of computerized psychodiagnostics and of objective personality tests are discussed. The paper's empirical section is focused on the utilization of Vienna Test System (VTS) in this area. Objective personality tests used for detection of risk-tendency were analysed and validised using the SPARO method and data gained during interviews. Empirically produced results suggest that the validity of the methods used is equivocal. One of the main conclusions of this thesis, therefore, is that VTS methods' potential to determine risk behaviour seems to be rather limited and its further research should be conducted in the future. Keywords: risk, risk-tendency, personality, objective personality tests, computerized testing, Vienna Test System
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Effect of exodermis differentiation on nutrient uptake localization in root
Janoušková, Jana ; Tylová, Edita (advisor) ; Konrádová, Hana (referee)
Plants are able to cope with changing environmental conditions or withstand its adverse effects due to their plastic development. One way to adapt to fluctuating amounts of nutrients and water in the environment or the presence of toxic substances is to regulate the movement of substances between the plant and the environment. Beside other, this regulation is also possible at the level of the root system, by the formation of apoplastic barriers endodermis and exodermis. Some species posses endodermis only, in others exodermis in hypodrermal layers of the root can be found. These barriers differentiate in three stages and prevent free movement of coumpounds though apoplast. The transport to the symplast is the key point of regulating the uptake of substances into the plant and the endodermis is the fundamental structure. The presence of exodermis, however, affects the apoplast permeability of the surface root layers and can therefore influence the involvement of the primary cortex cells in the uptake of substances from the environment. In this work the impact of phosphate deficiency on the formation of apoplastic barriers was studied focusing on exodermis and the effect of its differentiation on the occurrence of membrane transporters and involvement of primary cortex cells in the uptake of...
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Root apoplastic barriers in adverse environmental conditions.
Blascheová, Zuzana ; Tylová, Edita (advisor) ; Konrádová, Hana (referee)
Differentiation of apoplastic barriers in roots is affected by adverse environmental conditions (e.g. heavy metal toxicity, salinity or flooding). The apoplastic barriers, exodermis and endodermis, differ from each other in response to environmental conditions. The exodermis is more affected by these conditions and its occurence is more variable. The presence of differentiated barriers affects root transport features like uptake, accumulation and entrance of polutants or nutrients. Key words: apoplastic barriers, heavy metals, differentiation, root, Casparian strips, suberin lamellae
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Abiotic Stress Adaptation in Plantago: mechanisms of tolerance
Dvořáková, Iveta ; Konrádová, Hana (advisor) ; Lhotáková, Zuzana (referee)
Plants are exposed to many adverse factors during their life cycles. Abiotic stresses are significantly limiting plant growth and development. Abiotic stress response mechanisms involve compatible solute synthesis (e.g. sugars, sugar alcohols and amino acids). The aim of this study was to characterise the responses of plants from Plantago genus to different abiotic stresses (drought, salinity, cold and stress combination). The complete plants grew under in vitro conditions. I compared morphological parameters, selected metabolic parameters (carbohydrates balance and proline accumulation) under optimal conditions and stress exposure. This study was focused on plants from genus Plantago, because they differ from each other in their tolerance to the salinity. Both, the glycophyte and the halophyte species are described within this genus. Plantains produce besides widespread soluble carbohydrates (sucrose, glucose, fructose) also sugar alcohol sorbitol, which has been reported as a significant component of the stress response. In addition, the reaction of plants to different carbon and energy sources was tested. More severe growth inhibition of the glycophyte Plantago lanceolata compared to the halophyte P. maritima was observed under salt treatment. Significant accumulation of sorbitol was observed...
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The effect of meta-topolin application on Norway spruce somatic embryogenesis
Štěpánová, Nikola ; Konrádová, Hana (advisor) ; Eliášová, Kateřina (referee)
Somatic embryogenesis represents one of the possible methods of vegetative propagation in conifers, especially when traditional propagation ways fail. Several persistent problems prevent the wider use of this technology on a large scale (e.g. low number of high-quality somatic embryos (SE), limited stability of embryogenic capacity of cultures and many others), and even in relatively well experimentally mapped species. In order to contribute to the elimination of some weak points associated with this method, I studied the effect of change in the applied aromatic cytokinins during proliferation. I replaced usually used 6-benzylaminopurine (BAP) with its hydroxylated derivative - meta-topolin (mT). Literature data indicate that this substitution might represent a promising change that could have solve some of problems, e.g. insufficient number of somatic embryos formed or common problem with aging of embryogenic cultures. I worked with a stable, well-growing embryogenic line of Norway spruce (Picea abies (L.) Karst.) derived by our team (line C). I performed the detailed description of the line C development with the conclusion that it showed good embryogenic capacity along with a number of other characteristics common to the lines that were used as model ones in the past. For this reason, it is very...
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Mechanisms of resistance of plants from the genus Coffea to abiotic stresses
Skřivánek, Jakub ; Konrádová, Hana (advisor) ; Tylová, Edita (referee)
The genus Coffea is so specific by its distribution, requirements for environmental conditions and economic importance for humans that it is increasingly being studied as a model plant material. The thesis in the form of literary research is worked out in the context of the emerging climatic changes in order to give a comprehensive overview of the physiological responses of plants of the genus Coffea to three abiotic stresses - heat, cold and drought. The partial goal was to compare the resistance to these stresses of two economically significant species - Coffea arabica and Coffea canephora. We cannot generally say which species is more resilient, it always depends on a particular stress. Essential parts of the reaction to these stresses have proved to be carbohydrate accumulation and content dynamics. Key words: carbohydrates, climate change, Coffea, drought, extreme temperatures, stress
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How does the current climate change affect the phenology and physiology of selected Central European flood-plain forest tree species?
Vokálová, Karolína ; Lhotáková, Zuzana (advisor) ; Konrádová, Hana (referee)
Floodplain forests are biodiversity-rich ecosystems found in many parts of Central Europe near watercourses and are part-time flooded during the course of the year. Floodplain forests are currently facing changes in environment related to climate change, for example increasing temperature and drought, elevated CO2 levels and excessive flooding. Woody plants respond to these changes by shifting the spring phenological phases, increasingly earlier onset of bud break occurs among different tree. Furthermore, there are various physiological, anatomical and morphological adaptations to these changes, through which plants try to avoid their damage. The plant response to changing environment is influenced by many endogenous factors, such as the degree of tolerance to flooding, the type of wood structure, position of a species on the isohydry-anisohydry scale or plant age, in addition to external factors, to which an extent of stress factor effect and its duration belong. In the future, a further increases in the average temperature, the CO2 concentration in the atmosphere and above-average flooding are expected, therefore it is important to understand the complex reactions and adaptations of floodplain forest trees to these changes in order to manage effectively these ecosystems.
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