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Accumulation of Zn, Cd and Pb in Agriculturally Important Cereals and Their Possible Genetic Modifications
Jarolímková, Víta ; Macek, Tomáš (advisor) ; Rothová, Olga (referee)
Cadmium, lead and zinc are taken up by plants from soil and atmosphere. Afterwards, they are redistributed within the plant body and often deposited in the parts that are processed in the food industry. Vegetal food therefore considerably contributes to the acquisition of essential zinc, but also to the accumulation of toxic cadmium and lead in the human body. As zinc deficiency and, on the other hand, cadmium and lead intoxication are global problems, accumulation of these metals is a topical issue. Increase in zinc deposition and decrease in cadmium and lead accumulation can be reached not only by traditional breeding and soil modification, but also by gene engineering methods. Soon, Zn-biofortified crops prepared via traditional breeding will be tested on a large-scale; overexpression of zinc ligands is researched as well. However, use of cisgenic or transgenic expression of plant metal transporters is currently a rather unexplored topic; yet it has the potential to target both the need for Zn-biofortification and decrease in cadmium and lead accumulation in edible parts of crops.
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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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Role of brassinosteroids in plant response to drought stress
Trubanová, Nina ; Rothová, Olga (advisor) ; Urban, Milan (referee)
Brassinosteroids are steroid phytohormones with a wide range of effects. They improve survivance of plants exposed to drought stress, increase their resistence and yield therethrough. They regulate the response of plants directly (via synthesis of metabolits) and/or indirectly (via the induction of antioxidant compounds and enzymes), often in interaction with other phytohormones. Experiments studying influence of brassinosteroids on response of plants stressed with water deficit differ in several parameters. Their correct interpretation is complicated conseguently.
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Response of different genotypes of Zea mays L. and Vicia faba L. treated with brassinosteroids to water deficit
Kuklíková, Radka ; Rothová, Olga (advisor) ; Hnilička, František (referee)
This work monitors the response of plants to the application of a solution of synthetic brassinosteroid (5-fluor-3α,17β-dihydroxy-5α-pregnan-6-on) under drought stress conditions and subsequent restoration of water availability. The response of two plant species was monitored under six-day period of cessation of watering and under six-day period of renewed optimal water supply. The experiments were carried out on plants with different type of photosynthesis - C3 plant Vicia faba L. and C4 plant Zea mays L.. For both plant species, three varieties/genotypes were used. Photosynthetic, morphological and developmental characteristics were monitored. The brassinosteroid treatment influenced more the morphological than the photosynthetic characteristics. The content of photosynthetic pigments was influenced more than the chlorophyll fluorescence parameters. The differences in morphological characteristics between individual varieties/genotypes were observed. The response to the application of brassinosteroid was observed especially for drought-sensitive variety/genotype. Application of brassinosteroid caused increase of the dry mass of leaves and roots, the height to leaf , the height of the whole plant and its increment under stress and post-stress periods in both plant species. The content of...
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The role of manganese-stabilizing protein of photosystem II
Duchoslav, Miloš ; Rothová, Olga (referee) ; Fischer, Lukáš (advisor)
Miloš Duchoslav The role of manganese-stabilizing protein of photosystem II Abstract The appearance of oxygenic photosynthesis was a key event in the evolution of life on the Earth. All molecular oxygen in the atmosphere likely comes from a water-splitting reaction catalysed by the oxygen-evolving center of photosystem II. Photosystem II - a multisubunit protein-cofactor complex with a phylogeneticaly highly conserved structure - is embedded in the thylakoid membrane of chloroplasts and cyanobacteria. The mechanism of the photosynthetic water-splitting reaction, which occurs on the manganese cluster, has been widely investigated; however, it has not yet been fully understood. An essential role in the stabilization of the manganese cluster and in the facilitation of oxygen evolution is played by photosystem II extrinsic proteins that occur in thylakoid lumen. The most important among them is a manganese-stabilizing protein (MSP) that is present in all known oxyphototrophs. This protein is believed to have many functions: besides stabilizing the manganese cluster, it is also carbonic anhydrase activity, GTPase activity and regulation of the turnover of the D1 protein. The functions of the MSP are probably regulated through changes in its dynamic structure. The MSP is likely to take part in the regulation of...
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Karyotype evolution of velvet spiders (Araneae: Eresidae)
Forman, Martin ; Král, Jiří (advisor) ; Rothová, Olga (referee)
Presented study is aimed to determine basic trends of karyotype evolution in velvet spiders (Eresidae; Araneae). Eresids are burrowing spiders; they includes also some social species. Karyotypes of 16 species of the family Eresidae as well as 2 species of the other families of the superfamily Eresoidea, Hersiliidae and Oecobiidae, are presented. Furthermore, DNA content and base proportion was determined in 14 species. In two species, DNA content of sex chromosomes was also measured. Obtained results revealed considerable variability of diploid numbers, and sex chromosomes systems in eresids. Obtained karyotype data allow to divide eresids into four groups. Karyotypes of the genera Gandanameno, Dresserus and S. lineatus are close to proposed ancestral karyotype of entelegynae spiders and they show the ancestral state of karyotype in velvet spiders. Karyotypes of S. lineatus and E. annulipes differ substantially from other representatives of the genera Stegodyphus and Eresus which indicates paraphyly of these genera. Karyotypes of basal forms are formed by acrocentric chromosomes. Further evolution of eresid karyotypes included considerable reduction of diploid numbers as well as changes of chromosome morphology. Social species of the genus Stegodyphus show tendency to reduce diploid numbers by...
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