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Rozhovory přes kutikulu
KOUTKOVÁ, Simona
Leaves of the plants communicate with their environment on the interface formed by epidermis with stomata and cuticle. Cuticle layer, composed of cutin and waxes, represents a barrier, which protects a plant from excessive water loss, but not only this. The changes of these boundaries are dependent on the environmental conditions, especially light (PPFD) and ambient CO2 concentration (Ca). This work tries to answer these questions: How is the availability of CO2 inside the leaf (Ci) altered? How is the development of epidermis related to cuticle formation?
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The phenomenon of Foliar Water Uptake - mechanisms and consequences with a focus on temerate plant species
Oramová, Viktorie ; Lhotáková, Zuzana (advisor) ; Ponert, Jan (referee)
The ability of plants to absorb water through leaves has been a matter of the sientific discussion for a long time. Among the epiphytic species (tilandsies for example), reduced root system and foliar water uptake (FWU) is considered an adaptation for life in soil-less environment, and FWU is a necesssity. It was surprising, that the same ability has been discovered in plant species with normally developed root system. Over the time, new pieces of evidence about FWU in broad range of plant species has been published and FWU is getting universal for all plants, across the taxonomic groups or biomes, including temperate zone. The systematic focus on FWU and continuity of its research is lacking and therefore the knowledge about FWU is still only partial. This bachelor's thesis is focused on mechanisms of FWU and the leaf structures that may mediate it. The ability of water to pervade cuticle through aquatic pores is discussed, together with the possibility of water absorption by stomata, trichomes, hydathodes or epiphylic organisms. Another discussed topic is the use of this water by plant - improving of the water regime, refilling of the embolized xylem vessels, possible exudation by roots etc. The matter of FWU has other consequences on the ecosystem level, like in water cycle or the plant's...
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Mechanisms of epidermal cells polarization in plants.
Vojtíková, Zdeňka ; Žárský, Viktor (advisor) ; Soukup, Aleš (referee)
Plant epidermal cells form contact area of the plant, they protect it from impacts of surrounding environment and they mediate the communication with its neighbourhood. In the epidermis there are evenly distributed several cell types with quite specialized morphology (pavement cells, trichomes and guard cells) due to the polarization mechanisms. The cytoskeleton and signal molecules of ROP GTPase family promote the polarized growth. Thanks to polarized growth the cells reach their shapes. The cytoskeleton responds to the signal by expanding the cell, helps with targeting of the secretion to the sites of active growth and mediates polarized formation of the cell wall. On the upper side of the epidermis the cuticle and layer of epicuticular waxex is secreted. The secretion of cuticular components is baso-apicaly polarized. This work summarizes the mechanisms of the polarization in plant epidermal cells discoverd untill now.
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Cuticle, its formation and importance in resistance of plants to abiotic stress
Litkeiová, Veronika ; Hála, Michal (advisor) ; Tylová, Edita (referee)
Plants are daily exposed to stress, biotic or abiotic. Both of these types can be divided into several subgroups. This work is focused on plant cuticle, its formation and function in respect to abiotic stress resistance. The main factors, mentioned in this work, are drought, heat, UV radiation, excessive salinity or ozone exposure. The individual chapters focus on the composition, biosynthesis and changes in the build-up construction caused by certain types of stressors. A significant part is also devoted to cutin and cuticular waxes, which play an important role in plant protection and whose structure is also affected by abiotic stress. Phytohormones, especially abscisis acid, which had its application here, are also not omitted. In the final phase of the thesis, cuticular mutants are mentioned in connection with abiotic stress types illustrating the role and the importance of the cuticle layer. Key words: plants, cuticle, osmotic stress, abscisic acid, cutin, waxes
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Factors affecting deposition of selected antimicrobial substances into the egg structures
Pokorná, Monika ; Javůrková, Veronika (advisor) ; Svobodová, Jana (referee)
Both during the ovogenesis and immediately after the laying is a bird egg exposed to strong pressure from the microorganisms which are able to penetrate the egg through eggshell pores and infect its inner structures. With regard to the proved negative effects on hatchability, viability and phenotype of offspring, a cascade of obstacles has evolved which are able to minimize the risk of bacterial infection. The deposition of antimicrobial components into the eggshell and the egg white is considered to be one of them. A whole group of egg white proteins belong to them, among which lysozyme and ovotransferrin, which are also partially deposited into the eggshell and cuticular layer of the eggshell, dominate with their antimicrobial effect. The implication of the newest studies is that the microbial protection of the egg can be also performed by the eggshell pigments - biliverdin and protoporphyrin, which protect the egg from being colonized by microorganisms with an increased UV light and regulation of conductivity and water vapour condensation on the egg surface. Even though the presence of these antimicrobial components in different structures of the egg has been proved, there is no known comparative study which addresses the relation between deposition of selected antimicrobial components into...
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Visualization of cell structures in leaf cells of Malus domestica as a tool for study of Malus-Venturia inaequalis interactions
Zajícová, Iveta ; Schwarzerová, Kateřina (advisor) ; Mašková, Petra (referee)
Apple scab, the most serious disease of apple is caused by fungal pathogen Venturia inaequalis. Knowledge about the apple response to apple scab attack on the cellular and tissue level is insufficient. For studies of Malus-Venturia interaction on the cellular and tissue level, the establishment of methods for cell structures visualization in apple leaves is necessary. In this work, the experimental plant material grown in vitro and ex vitro was successfully established and the method of apple infection by conidia of V. inaequalis was optimized. Various methods of cell components visualization such as vital staining, in situ immunolocalization, transformation, environmental scanning electron microscopy and confocal microscopy, were tested. Cell structures, such as the cytoskeleton, the cell wall and the cuticle were visualized in apple leaves. Preliminary experiments following specific the changes of cell wall structures induced by V. inaequalis attack were performed. Further, changes of cuticle structure, the first barrier for penetration of pathogen to plant tissues during infection, were observed during the leaf ontogenesis. Powered by TCPDF (www.tcpdf.org)
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Mechanisms of epidermal cells polarization in plants.
Vojtíková, Zdeňka ; Žárský, Viktor (advisor) ; Soukup, Aleš (referee)
Plant epidermal cells form contact area of the plant, they protect it from impacts of surrounding environment and they mediate the communication with its neighbourhood. In the epidermis there are evenly distributed several cell types with quite specialized morphology (pavement cells, trichomes and guard cells) due to the polarization mechanisms. The cytoskeleton and signal molecules of ROP GTPase family promote the polarized growth. Thanks to polarized growth the cells reach their shapes. The cytoskeleton responds to the signal by expanding the cell, helps with targeting of the secretion to the sites of active growth and mediates polarized formation of the cell wall. On the upper side of the epidermis the cuticle and layer of epicuticular waxex is secreted. The secretion of cuticular components is baso-apicaly polarized. This work summarizes the mechanisms of the polarization in plant epidermal cells discoverd untill now.
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Carbon dioxide transport through the hypostomatous plant leaf
JANOVÁ, 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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