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The effects of irradiation on plant photomorphogenesis in highschool biological education
Sedlecký, Libor ; Albrechtová, Jana (advisor) ; Pavlová, Libuše (referee)
Light does not serve plants only as a source of energy, but it mediates the information about the environmental conditions and brings signal information for developmental processes taking place in plants. Radiation within the whole spectrum range can be produced by a natural source, or an artificial source. Radiation is percived by a plant due to the whole range of receptors, known as photoreceptors - receptor molecules. Because of photoreceptors plant is able to adapt to its enviromnent and to adjust its metabolism to be as effective as possible. In photomorphogenetic reactions a plant responds mostly to red, blue and partly ultraviolet part of electromagnetic spectrum. For the red radiation there is only one receptor - phytochrome, existing in two various conformations and in several species. Phytochrome is one of the most studied photoreceptors. Blue visible light and partly also ultraviolet radiation is therefore percieved through cryptochromes, which were resistant to research for a long time. In photomorfogenesis there is an enormous difference in plant reactions to light and dark condition. Very different response is observed in various radiation conditions and different physiological events are triggerred and take place. One of the main reactions occurring during change from dark to light...
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Role genu ABA1 ve fotomorfogenezi rostlin
Malysheva, Yuliia
Plant hormones belong to the group of growth regulators that play an irreplaceable role in plant growth and development. One of them is abscisic acid (ABA) that func-tions in many developmental processes, including stress responses or skotomorphogenesis. Zeaxanthin epoxidase (ABA1) plays an important role in the ABA biosynthesis and is required for the resistance to osmotic and drought stresses, ABA-dependent stomatal closure, seed dormancy and disease resistance. How-ever, the role of ABA1 in photomorphogenesis remains unclear. The base of this work was a selection of homozygous aba1-1 mutant in the Col-0 genetic background that was characterized under dark, low light and standard light conditions. The aba1-3 mutants in Ler-0 displayed reduced hypocotyl growth during late skotomorphogenic growth whereas reduction of hypocotyl length after exogenous application of cytokinin absent-ed compared to wild-type. In contrast, only small differences in hypocotyl growth were found between wild-type seedlings and ABA-deficient mutants during photomorpho-genesis. Interestingly, the treatment by exogenous cytokinin led to longer hypocotyls of aba1-3 mutant compared to wild-type. Analysis of the interaction of ABA and cytokinins revealed that cytokinins could revert some negative effects of ABA tre-atment like germination. It was shown that ABA and cytokinins orchestrate together the regulation of the growth and development of the seedlings.
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Štúdium interakcie rastlinných hormónov cytokinínov a signálnej dráhy UV svetla
Kameniarová, Michaela
Photomorphogenesis is a developmental process in which plants change their growth and morphology in response to the light conditions. Besides the visible part of the light, photomorphogenic responses are also mediated by UV light. UV light responses include hypocotyl growth inhibition, cotyledon extension and biosynthesis of flavonoids. Another important factor in photomorphogenesis are the plant hormones cytokinins which affect many aspects of plant life. The aim of the bachelor thesis was description of interactions of cytokinins with the signalling pathway of UV light. Perception of UV light is mediated by photoreceptor UVR8. The effect of exogenous CK addition on the expression of selected CK and UVR8 regulated genes was monitored by RT-qPCR in 7 days-old Arabidopsis thaliana seedlings with mutation in UVR8, and the effect of CK on the growth of their roots and hypocotyls was monitored as well. Gene expression analysis showed that the mutation in UVR8 gene interfere with cytokinin signalling.
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Fotomorfogeneze: the effects of irradiation on plant development in the eductational programs of basic schools and highschools
Sedlecký, Libor ; Albrechtová, Jana (advisor) ; Janštová, Vanda (referee)
The main aim of this diploma thesis was creation of functional experiments and supporting teaching materials for high school students which would clearly demonstrate the processes of photomorphogenesis in plants. Proposed experiments had to be verified in practice on the basis of their reliability, repeatability and reproducibility in schools. It was necessary to drew up the educational materials for each experiment focused on observation of photomorphogenesis plant's reactions. These materials give students the basics of scientific work and specifically they increase the interest in experimental plant biology. The first part of the thesis is literary introduction that provides the theoretical background to the topic of photomorphogenesis for teachers. It summarizes the current of the art mechanisms and manifestations of photomorphogenesis processes of plants. The second didactic part of the introduction deals with the framing up teaching of plant physiology into current curricula of education in the Czech Republic. For the formativ of educational materials experiments had to be designed to demonstrate reliably basic photomorphogenetical processes. Three experiments were designe dat: 1. plant phototropism, 2. negative plant phototropism and 3. plant scotomorphogenesis.To select these experiments I...
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The effects of irradiation on plant photomorphogenesis in highschool biological education
Sedlecký, Libor ; Albrechtová, Jana (advisor) ; Pavlová, Libuše (referee)
Light does not serve plants only as a source of energy, but it mediates the information about the environmental conditions and brings signal information for developmental processes taking place in plants. Radiation within the whole spectrum range can be produced by a natural source, or an artificial source. Radiation is percived by a plant due to the whole range of receptors, known as photoreceptors - receptor molecules. Because of photoreceptors plant is able to adapt to its enviromnent and to adjust its metabolism to be as effective as possible. In photomorphogenetic reactions a plant responds mostly to red, blue and partly ultraviolet part of electromagnetic spectrum. For the red radiation there is only one receptor - phytochrome, existing in two various conformations and in several species. Phytochrome is one of the most studied photoreceptors. Blue visible light and partly also ultraviolet radiation is therefore percieved through cryptochromes, which were resistant to research for a long time. In photomorfogenesis there is an enormous difference in plant reactions to light and dark condition. Very different response is observed in various radiation conditions and different physiological events are triggerred and take place. One of the main reactions occurring during change from dark to light...
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