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Physiological mechanisms of sorghum adaptation to abiotic stresses
Kratochvíl, Jan ; Konrádová, Hana (advisor) ; Lhotáková, Zuzana (referee)
Sorghum is a traditional crop, which has been grown especially in the countries of Africa and Asia. It is used as a food, fodder, source of fiber and energy. Because of its tolerance to various abiotic stresses, especially drought, sorghum is often called "the camel of crops", and there are a lot of studies trying to clarify the basis of this tolerance. Nowadays, suitable sorghum genotypes are considered as an alternative in other parts of the world (North and Middle America, Europe) or to widen the planting areas. The first part of this thesis summarizes results of current studies aimed on sorghum physiological responses to drought, high salinity, extreme temperatures, aluminium toxicity and the combination of these stresses. The second part explains the ways how to alleviate effect of stresses on the plant. It includes the application of various compounds and genetic modifications. Powered by TCPDF (www.tcpdf.org)
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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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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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Analysis of parameters presumably associated with drought-resistance in various sorghum genotypes
Panchártek, Daniel ; Holá, Dana (advisor) ; Hniličková, Helena (referee)
The aims of this work were 1) to assess whether sorghum (Sorghum bicolor (L.) Moench) genotypes originating from the India can be grown and analyzed in the climatic conditions of central Europe and 2) to find out the utilization potential of selected non- destructive and destructive methods based mostly on the chlorophyll a fluorescence measurements and the determination of photosynthetic pigments' content for the differentiation of sorghum genotypes based on their presumed drought tolerance. Field experiments made during 2 years compared 15 genotypes of this species (2 stay-green parental lines, 2 senescent parental lines and 11 introgression lines with stay-green loci), 2 of these genotypes were further analyzed in greenhouse conditions where the water deficit was induced by a cessation of watering for 12 days. The field-grown plants showed some differences between individual genotypes in all measured parameters; however, for the majority of the genotypes these differences were not statistically significant. The stay-green parental genotype B35 differred the most from the other ones in both field seasons, but the other stay-green genotypes usually did not differ from the senescent genotypes. No significant differences between both greenhouse-tested genotypes (presumably contrasting in their...
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Analysis of antioxidant systems, morphological and physiological parameters in two faba bean (Vicia faba L.) cultivars during drought stress
Jelénková, Iva ; Kočová, Marie (advisor) ; Wilhelmová, Naďa (referee)
Knowledge of physiological and morfological mechanisms which are related to drought tolerance is essential in breeding high-yielding and tolerant plants, which would not suffer unfavourable environmental conditions. Drought stress can lead to oxidative damage which causes serious disorders in physiological and biochemical processes in plant cells. Antioxidants can reduce those negative effects. Morphological (dry mass of shoot and roots, height of shoot, number of leaves), physiological (photosynthetic efficiency, pigment content, relative water content-RWC) and antioxidative (catalase-CAT, ascorbate peroxidase-APX, proline) parameters were evaluated in this study using two genotypes of Vicia faba L. differing in drought susceptibility. Drought resistant (Merkur) and sensitive (Piešťanský) genotypes were exposed to 10 days of drought. Activity of CAT and APX of stressed plants rather decreased. Proline content oscillated and no evident trend or significant differences were observed in relation to drought stress. Decrease in RWC was expressed more at susceptible plants, electron-transport chain activity and pigment content were not affected much by drought. Drought susceptible genotype expressed more serious negative effects of drought in morphological parameters, however this genotype was a bit bigger than...
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The municipality solution analysis in readiness for extraordinary situation drought in the South Bohemia region.
FURIK, Miroslav
The aim of this diploma thesis is to evaluate the needs and preparedness of municipalities with extended competence of the South Bohemian Region for an extraordinary event of drought. To achieve the stated goal, a search of available literature and foreign sources was carried out, which helped obtain the basic information necessary to understand this issue. A qualitative research method based on a structured interview was used to analyze the needs and readiness of municipalities with extended competence. This research was carried out among the crisis management personnel of municipalities with extended competence in the territory of the South Bohemian Region. Other experts such as those involved in the crisis management department of the South Bohemian Regional Office, the Department of the Environment of Municipalities with Extended Powers or the Fire Brigade of the South Bohemian Region were also questioned. The available documents also examined details of selected aspects that increase the resilience and preparedness of municipalities with extended jurisdiction for drought. These documents examined the extent of involvement of state administration and self-government in drought preparedness issues and the way of implementation in the analyzed documents. Afterwards, the information collected was arranged and evaluated. The research has shown that the preparedness of the municipalities with extended powers for the extraordinary event of drought is insufficient. Documentation dealing with drought issues has not been elaborated for individual administrative districts of municipalities with extended competence and has not been incorporated in the emergency plan of the region or the crisis plan of the municipality with extended competence. Another problem is the insufficient information of municipalities with extended competence on drought episodes in the administrative districts of municipalities with extended competence in the territory of the South Bohemian Region. The research also identified a problem with a low number of drinking water sources and insufficient provision of alternative or emergency drinking water sources.
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Increase in Winter Air Temperatures in the Czech Republic between 1961 and 2010
Střeštík, Jaroslav ; Rožnovský, J. ; Štěpánek, Petr ; Zahradníček, Pavel
Based on the analysis of average monthly air temperatures between 1961 and 2010 it can be statistically proven that there is an increasing trend. The actual level of increase, however, is different for each season and is also specific for a particular region – there are differences between Bohemia and Moravia. In the summer, the average monthly air temperatures rise more significantly in Moravia, where there is a higher number of stations with increase of over 1°C compared to Bohemia. This is also true for the spring, for which the difference is not so profound, and is yet smaller in the autumn. In contrast, in the winter there is a more significant increase in Bohemia, where most stations show an increase of over 0.5°C. In Moravia the increase is usually only around 0.3 to 0.4°C. Differences between the increases of average air temperature can also be seen across the individual winter months. Highest increase was found in January, where some stations in Bohemia show an increase of over 1°C, a value that was not observed in Moravia, where some stations have an increase of less than 0.8°C. In December and February, the level of increase in general is much smaller. However, given the predicted increase of air temperatures in the future in general, it can be expected that in the upcoming decades the number of warm winters will increase. Such increase of air temperatures in the winter is likely to have negative impacts for the agriculture.
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Genetically modified plants for future of globally warmed planet
Nedělová, Jana ; Opatrný, Zdeněk (advisor) ; Nátr, Lubomír (referee)
Many problems which have an adverse impact on crops, come into the agriculture with global warming the planet and thus changes in regional temperature and humidity regimes. These problems will be significant especially in developing countries that are already interfered by drought and threatened by famine. Therefore major target is developing of plants resistant to these climatic changes. Only the very classical breeding doesn't clearly sufficient for these tasks. However, genetic engineering could contribute significantly by genetically modified (GM) plants. This modern breeding-cultivation technology has several advantages in comparison with traditional breeding. One of them is for example targeted and well-controlled change in genotype, which allows obtaining plants with specific desired properties.
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Drought, stress and resistance
Kettnerová, Karolína ; Zelenková, Sylva (advisor) ; Rothová, Olga (referee)
This bachleor thesis focuses on the influence of water deficit on plants. The causes of the origins of water deficit and its impact on growth and development of plants are described. Attention is paid to the process of stress response and to the adaptation mechanisms which aimed to induce stress tolerance. Separate chapters are devoted to the cuticle and stomata, two important regulators of plant water loss. The thesis also focuses on the phenomenon of osmotic adjustment which relates to the accumulation of compatible solutes. Signalling pathways induced water shortages, change in gene expression, synthesis of special proteins and consequences of secondary oxidative stress are all covered. Key words: drought, water deficit, stress, stress tolerance, stomata, cuticle, osmotic adjustment, compatible solutes, signal transduction
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