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Dynamics of cold regulated proteins during cold acclimation in cereals
Vítámvás, Pavel ; Prášil, Ilja (advisor) ; Honys, David (referee) ; Smýkal, Petr (referee)
The aim of this dissertation was to study the mechanism of cold acclimation via the dynamics of cold regulated proteins (such as WCS120 or DHN5) in different frost- tolerant wheat and barley cultivars. Mass spectrometry analysis of a total sample of proteins, soluble upon boiling, showed qualitative differences between cold-acclimated (e.g., 7 COR proteins) and non-acclimated (e.g., only 3 COR proteins) samples of the winter wheat Mironovskaya 808. Furthermore, by 2-DE or W-blot analysis, there were found quantitative differences in the accumulation of WCS120 proteins between cultivars, grown under different time, photoperiod, and/or temperature conditions. The higher levels of WCS120 proteins are associated with higher frost tolerance of cultivars, grown under constant and low temperature. However, the dynamics of WCS120 proteins during long-term cold-acclimation, with periods of de-acclimation and re- acclimation, demonstrated that plants with the same level of frost tolerance could be distinguished by the level of accumulation of the WCS120 proteins. These results indicated that developmental genes influence the ability to re-accumulate WCS120 proteins by the partial vernalization of plants, while the ability to induce high frost tolerance was only influenced by the saturation of vernalization....
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Different response of maize inbred and hybrid genotypes to drought: analysis of leaf proteome and photosynthetic processes
Benešová, Monika ; Holá, Dana (advisor) ; Prášil, Ilja (referee) ; Pospíšilová, Jana (referee)
Drought is one of the most important stress factors affecting plants. Increasing drought resistance via plant breeding is currently the main approach for improvement of plant productivity and reduction of water usage. Plant breeders and scientists search for reliable and easy methods of the determination of drought sensitivity in different genotypes. A precise knowledge about processes underlying plant stress response and defence against limited water availability is necessary for this. The aim of this study was a detailed analysis of photosynthetic processes and changes in leaf proteome (again aimed especially at proteins involved in photosynthesis) during drought stress. This analysis was a part of a complex project focused on the possible causes of genetic variability and drought resistance in agronomically important crops. Another goal was to analyse whether the measurement of selected photosynthetic parameters can be used for the determination of drought sensitivity per se and/or for the prediction of the response of hybrids based on known behaviour of their parents. Young plants of maize inbred lines and their hybrids were used as a model for this analysis, which was made under conditions of moderate and more severe drought. Two inbred lines which were (together with their F1 hybrids) used...
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Antioxidant enzymes response to abiotic stress. Impact of decreased cytokinin level.
Lubovská, Zuzana ; Wilhelmová, Naďa (advisor) ; Prášil, Ilja (referee) ; Kočová, Marie (referee)
Charles University in Prague, Faculty of Science Department of Experimetnal Plant Biology Ph.D. study program: Plant physiology and anatomy Abstract Antioxidant enzymes response to abiotic stress. Impact of decreased cytokinin level. Zuzana Lubovská Supervisor: RNDr. Naďa Wilhelmová, CSc. Supervisor-consultant: RNDr. Helena Štorchová, CSc. Praha, 2015 The response of the antioxidant enzyme system to drought, heat and a combination of these stresses was followed in tobacco plants overexpressing cytokinin oxidase/dehydrogenase1 (CKX1) under the root-specific WRKY6 promoter (W6:CKX1 plants) and under the constitutive 35S promoter (35S:CKX1 plants) and in the corresponding wild type (WT). CKX1 over-producing lines developed a bigger root system, which contributed to their stress tolerance. The high stress tolerance of 35S:CKX1 plants was also associated with a dwarf shoot phenotype and changed leaf morphology. The genes for chloroplastic antioxidant enzymes, stroma ascorbate peroxidase (sAPX), thylakoid ascorbate peroxidase (tAPX) and chloroplastic superoxide dismutase (FeSOD), which are responsible for scavenging of reactive oxygen species produced via electron transfer during photosynthesis, were all strongly transcribed in control conditions. All the tested stresses down-regulated expression of these genes...
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Plant responses to low temperatures, resistance and damage
Kabilková, Eva ; Prášil, Ilja (advisor) ; Hála, Michal (referee)
Plants can encounter many stressors throughout their lives, including low temperatures. This work characterizes the limits of extreme temperatures that have an effect on plants; cold (temperatures ranging from 0 ř C to 15 ř C) and frost (temperatures below 0 ř C accompanied by ice formation in plant tissues). Consequences of plant damage caused by extreme temperatures are also given, as well as the most important plant resistance and defense mechanisms in response to these stressors, especially at the cellular level. These are temperature responding signalling transduction pathways leading to the activation of stress genes and some phytohormones (abscisic acid, salicylic acid, jasmonates), as well as the accumulation of stress proteins (e.g. anti-freezing proteins, dehydrins). At the same time, some of the impacts of climate change, including global warming, on selected plants species are mentioned. Key words: stress, plants resistance, tolerance, low temperature, cold, frost, damage to plants
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Response to repeated exposure to selected abiotic stress factors in two subspecies of olive
Skřivánek, Jakub ; Konrádová, Hana (advisor) ; Prášil, Ilja (referee)
Olive tree (Olea europaea L.) is one of the world's oldest domesticated crops, a long-living tree capable to of withstand periods of high temperatures with limited water supply, deteriorated soil conditions, but also exposure to freezing temperatures during winters. The work is focused on the characterization of stress responses of olives to selected stress factors (drought, salinity, cold) at the level of antioxidant systems and aims to answer the question whether the nature of these responses changes due to repeated exposure to the stress factor. In many plants, an important component of the stress response is the adaptation of carbohydrate balance, including changes in the total carbohydrate content as well as in their spectrum. Due to the potential of soluble carbohydrates to quench free radicals and due to the diversity of the olive carbohydrate spectrum, special attention has been paid to the study of accumulation of individual groups of carbohydrates with protective potential. We have optimized experimental in vitro cultivation conditions for two subspecies of olive tree - domesticated (Picual cultivar) and wild one (ssp. laperrinei). It was impossible to find conditions ensuring satisfactory growth of the photoautotrophic culture. In experiments simulating the water shortage by adding PEG...
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Resynthesis of oilseed rape from Brassica rapa and Brassica oleracea
Klíma, Miroslav ; Hilgert-Delgado, Alois ; Ulvrová, Tereza ; Bryxová, Pavla ; Vítámvás, Pavel ; Prášil, Ilja Tom ; Kosová, Klára
In order to extend the variability of the genofond, so-called resynthesis can be used, when new genotypes are created by crossing selected Brassica rapa and B. oleracea, by early isolation of immature embryos from young eggs and their in vitro fertilization (Hilgert-Delgado et al., 2015). It has been shown that resyntetized genotypes are distinct from rape materials grown at present (Sosnowska et al., 2010), so that they can serve as a source of new variability in breeding programs focusing on cytoplasmic and pollen sterility, resistance to pathogens and tolerance to stresses (Warwick et al., 2009). Representatives of the initial components are characterized by wide variability in terms of morphology and agronomic characteristics, and are a prospective source of heterosis and other traits (Wu et al. The use of resyntetized genotypes for the direct production of rapeseed varieties is not possible due to the poor quality of the seed of these materials. It is mainly the high content of glucosinolates and erucic acid, typical of most of the initial components (Jesske et al., 2013). However, the required properties can be transferred by crossing to conventional breeding materials (Hilgert-Delgado et al., 2017).
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Dynamics of cold regulated proteins during cold acclimation in cereals
Vítámvás, Pavel ; Prášil, Ilja (advisor) ; Honys, David (referee) ; Smýkal, Petr (referee)
The aim of this dissertation was to study the mechanism of cold acclimation via the dynamics of cold regulated proteins (such as WCS120 or DHN5) in different frost- tolerant wheat and barley cultivars. Mass spectrometry analysis of a total sample of proteins, soluble upon boiling, showed qualitative differences between cold-acclimated (e.g., 7 COR proteins) and non-acclimated (e.g., only 3 COR proteins) samples of the winter wheat Mironovskaya 808. Furthermore, by 2-DE or W-blot analysis, there were found quantitative differences in the accumulation of WCS120 proteins between cultivars, grown under different time, photoperiod, and/or temperature conditions. The higher levels of WCS120 proteins are associated with higher frost tolerance of cultivars, grown under constant and low temperature. However, the dynamics of WCS120 proteins during long-term cold-acclimation, with periods of de-acclimation and re- acclimation, demonstrated that plants with the same level of frost tolerance could be distinguished by the level of accumulation of the WCS120 proteins. These results indicated that developmental genes influence the ability to re-accumulate WCS120 proteins by the partial vernalization of plants, while the ability to induce high frost tolerance was only influenced by the saturation of vernalization....
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