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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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Physiological mechanisms of abiotic stress tolerance in Sorghum bicolor
Kratochvíl, Jan ; Konrádová, Hana (advisor) ; Lhotáková, Zuzana (referee)
Current agriculture is facing a serious challenge of decreasing precipitation and irregular occurrence of drought periods including their unfavorable distribution during the vegetation season. This leads to growing interest in planting highly drought-resistant crops like sorghum. In comparison with other crops, sorghum excels in low water demand, though exhibits high susceptibility to low temperatures, which hampers its spread to new regions. Surprisingly, there is not enough information about the nature of sorghum's reaction to cold exposure. The aim of this diploma thesis was to describe reactions of young sorghum plants exposed to cold stress, low water availability and their combination and to verify the possibility of plant hardening through previous low-stress load. The special focus was paid to changes in carbohydrate metabolism, which plays generally very important role in plant defense reactions. The other analyzed physiological traits were leaf tissue osmotic potential, proline content and basic morphometric characteristics. Experimental design consisted of pot experiments conducted in growth chambers and the experiments performed under controlled conditions in vitro, using two sorghum genotypes "Ruzrok" and "01Z1800012". Both genotypes exhibited similar response to stress treatment....
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Water use efficiency (WUE), its definition and importance in plant resistance against osmotic stress
Jedlička, Tomáš ; Hála, Michal (advisor) ; Lhotáková, Zuzana (referee)
Water is one of the main limiting factors of plant growth. Availability of water on our planet is reduced, and if we add fast-growing human population, we have a problem brewing. Scientists from all around the world, especially those from arid regions, are facing a big problem, which is an attempt to make the most efficient use of water by plants. If this problem should be solved, we need to understand the issue of Water Use Efficiency (WUE). This paper attempts to summarize the current knowledge related to the issue of WUE, mainly focused on anatomical and physiological parameters control of WUE, which is focused primarily on the issue of evapotranspiration. Another part focuses on clarifying the issue of WUE at the gene level and the related biotech opportunities. At the end of the work are discussed possibilities of increasing WUE using irrigation techniques.
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Water use efficiency (WUE), its definition and importance in plant resistance against osmotic stress
Jedlička, Tomáš ; Hála, Michal (advisor) ; Lhotáková, Zuzana (referee)
Water is one of the main limiting factors of plant growth. Availability of water on our planet is decreasing, and if we add fast-growing human population, we have a problem growing. Scientists from all around the world, especially those from arid regions, are facing a big problem, which is an attempt to make the most efficient use of water by plants. If this problem should be solved, we need to understand the issue of Water Use Efficiency (WUE). This paper attempts to summarize the current knowledge related to the issue of WUE, mainly focused on anatomical and physiological parameters control of WUE, which is focused primarily on the issue of evapotranspiration. Another part focuses on clarifying the issue of WUE at the gene level and the related biotech opportunities. At the end of the work are discussed possibilities of increasing WUE using irrigation techniques. Key words: water use efficiency, evaporation, transpiration, stoma, stomatal density, abscisic acid, ERECTA
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Role of the yxkO gene of Bacillus subtilis in responce to environmental stress.
Petrovová, Miroslava ; Lichá, Irena (advisor) ; Nešvera, Jan (referee)
ROLE OF THE YXKO GENE OF BACILLUS SUBTILIS IN RESPONCE TO ENVIRONMENTAL STRESS Abstract Mutation of the yxkO gene, which encodes a putative ribokinase and belongs to the σB general stress response regulon, leads to reduced salt tolerance under potassium limitation in Bacillus subtilis. The biological function of the yxkO gene has not been determined yet, but it may be involved in the high affinity potassium uptake system, which has been described in Escherichia coli in contrast to Bacillus subtilis. Our goal was to describe another features of a mutant in the yxkO gene and to try to propose the role of this gene. Using the integration vector pMutin4, we prepared a Bacillus subtilis strain MP2 with a yxkO gene inactivation. The MP2 strain displays limited growth in a rich medium and it is a sensitive strain to tetracycline. Furthermore, this strain is unable to form endospores and the cells are longer, which indicates a septum formation defect. We accomplished a 2-D protein gel analysis to compare expression profiles of the MP2 strain and the 1A680 standard strain after salt and ethanol stress. The MP2 strain shows changes in productions of some energy metabolism enzymes and flagellin protein. We conclude that yxkO is a regulatory gene, whose product has a pleiotropic effect on many of cell functions.
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Vliv osmotického stresu na růst rostlin bramboru v in vitro podmínkách
Franek, Ondřej
Osmotic stress influences productivity and crop yield of plants significantly. This bachelor thesis is a literature review summarizing the acclimation of plants under osmotic stress and tolerance of plants to osmotic stress, observes issues of abscisic acid in the relation to osmotic stress and other markers as osmoprotectants and dehydrins. Screening experiment in vitro culture of potato plants (Solanum tuberosum L.) in agar stiffened media containing stressors as sodium chloride, sucrose and polyethylene glycol was carried. Plant growth parameters such as solids content and length of roots was observed. RIA method was used to determine the content of abscisic acid in plant leaves influenced by stressors.
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