National Repository of Grey Literature 50 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Physiological basis of the tradeoff between growth and defense against abiotic stress: the role of carbon balance
Doložílek, Jakub ; Konrádová, Hana (advisor) ; Petrášek, Jan (referee)
Similarly to other organisms, plants must coordinate growth and development with their energetic status. Besides that, considering their sessile way of life, they need to adapt very precisely to the environmental conditions of their habitats. However, from the point of view of invested resources, the defence mechanisms may be very expensive, and so, their activation is usually accompanied by a restriction of growth. Hence, establishing functional dynamic balance between investment to growth and defensive reactions ("G-D tradeoff") is essential for the plants fitness, competitiveness and reproduction success. The thesis examines the mechanisms that are fundamentally contributing to this balancing. In this work, evolutionarily conserved axis coordinating growth and development with energetic status consisting of TOR kinase, positive growth regulator during favourable conditions, and her antagonist, the SnRK kinase, inducer of resources mobilization in purpose of realizing defensive measures securing energetic homeostasis, is discussed. Further, this thesis focuses on plant-specific pathway which links the TOR-SnRK1 axis with perception of environmental conditions. The main components of this pathway are the SnRK2 kinases, coordinators of specific defensive reactions, PP2C phosphatases and...
Role of TCTP1 in plant reproduction
Pitoňak, Oliver ; Hafidh, Said (advisor) ; Lafon Placette, Clément (referee)
TCTP is a conserved eukaryotic protein involved in regulation of multiple cellular processes, such as translation, cell cycle and cell death. Apart from its intracellular functions, TCTP is secreted and participates in human immune response. Dimerization via a terminal cysteine residue is critical for its extracellular function. Multiple sequence alignment of eukaryotic TCTPs revealed that terminal cysteine residue is conserved not only in animals but also in green plant lineage. In contrast to animal model organisms, knowledge about TCTP in plants is limited. Arabidopsis thaliana genome harbors two TCTP paralogs, TCTP1 and TCTP2. TCTP1 expression is highly upregulated in pollen. Previously published studies pointed to its role in embryo development, pollen tube growth and targeting. Using mutant characterization and analysis of subcellular localization, the role of TCTP1 in plant reproduction was investigated in this thesis. Recombinant Arabidopsis thaliana TCTP1 protein was produced along with its potential interacting partners BRL2 and TTL3 in heterologous Escherichia coli system. tctp-1 T- DNA line characterization pointed to TCTP1 role in pollen tube growth. It was expressed in mature pollen and pollen tube under native promoter and localized to the cytoplasm. Recombinant AtTCTP1 formed dimers...
Relationship between pollen diversity and floristic diversity - utilization for study of the past
Koďousková, Lucie ; Kuneš, Petr (advisor) ; Prach, Jindřich (referee)
This thesis deals with the relationship between palynological diversity and floristic diversity. Diversity is complex quantity, which consists of a number of species, the number of individuals and relative frequency of species known as evenness. It characterizes the diversity at the species level, genetic level or within communities. Its relationship with palynological diversity is problematic, especially because of lack of taxonomic precision in palynology, species-specific differences in pollen production and dispersal and sample size, since the number of taxa increases with sample size. The thesis also focuses on the studies which tried to prove positive correlation between palynological and floristic diversity, including techniques used. The second part describes methodology of collecting vegetational and palynological data and the treatment of sampes.
Pollens of Selected Alergenic Plants and their Didactic Use in Teaching Biology at High Schools
Pýchová, Adéla ; Skýbová, Jana (advisor) ; Říhová, Dagmar (referee)
In my thesis I deal with the pollen of allergenic plants, the origin and proces of allergy to plant pollen and the inclusion of these topics in the teaching of plant biology in high schools. In the theoretical part I focus on topic of pollen allergy. First, I generally describe allergy and its origin, causes of allergic diseases, environmental factors and the development of allergic disease. I also briefly address the naming and registration of allergens and I also mention the so-called cross-allergy. Great emphasis is placed on pollen allergy, which is devoted to a larger unit, divided into individual subchapters dealing with the physiological function of the nose, followed by an allergic reaction of type I, an allergic reaction that occurs on the nasal mucosa. Furthermore, subchapters mentioning the classification of allergic rhinitis, diagnosis and pharmacotherapy, including additions to the drug groups used in the treatment of pollen allergy. Another larger unit is devoted to the structure of the plant's blossom as a source of allergen, which includes the anatomy of the blossom parts and a description of the pollen grain. The anatomical description of the blossom is followed by a practical part, first created by a tabular overview with selected allergenic plants. Each plant causing the allergy...
Functional characterization of Alba-family genes in Arabidopsis thaliana
Kočová, Helena ; Honys, David (advisor) ; Fischer, Lukáš (referee)
(anglicky) Alba-family proteins were identified in Archaea and Eucarya and are classified among the oldest and the most conserved nucleic acid-binding proteins. The binding preferences and roles differ among certain evolution clades. In Crenarchaea they represent chromatin-binding proteins, while their role in RNA metabolism is suggested in Euryarchaea and Eukaryotes. ALBA proteins are well characterized in human, where they play a role in the RNAse P/MRP complex and in unicellular parasites, such as Plasmodium and Trypanosoma, where an involvement in the life cycle regulation is confirmed. In plants, their role is not yet well understood. The aim of this thesis is to increase a knowledge about the Alba-family proteins in the model plant Arabidopsis thaliana. Based on a minimal changes to development and reproduction in single mutants and high sequence similarity, a functional redundancy of the proteins was assumed. For better understanding of the ALBA proteins function, three smaller members of the family were edited by the same metod. The obtained triple mutant showed delay in flowering. ALBA dimer formation was confirmed in many organisms. BiFC method was used to determine Arabidopsis ALBA homodimerization. The data analysis showed potential homodimerization in most of them.
Studying dimer formation and effectors of Arabidopsis thaliana nascent polypeptide-associated complex
Klodová, Božena ; Fíla, Jan (advisor) ; Robert Boisivon, Helene (referee)
The development of plant flowers represents a complex process controlled by numerous mechanisms. The creation of double homozygous mutant of both β subunits (sometimes also referred to as basic transcription factor 3) of nascent polypeptide associated complex in Arabidopsis thaliana (further referred to as nacβ1 nacβ2) caused quite a strong defective phenotype including abnormal number of flower organs, shorter siliques with a reduced seed set, and inferior pollen germination rate together with a lower ovule targeting efficiency. Previously, NAC complex was described to be formed as a heterodimer composed of an α- and β-subunit, which binds ribosome and acts as a chaperone in Saccharomyces cerevisiae. In plants, NACβ is connected to stress tolerance and to plant development as a transcription regulator. However, little is known of NAC heterodimer function in plants. In this thesis, yeast two hybrid system (Y2H) and bimolecular fluorescence complementation (BiFC) assays were used to verify the NAC heterodimer formation in A. thaliana and to establish any potential interaction preferences between both NACβ paralogues and five NACα paralogues. To deepen the understanding about molecular mechanisms behind the nacβ1 nacβ2 phenotype, flower bud transcriptome of the nacβ1 nacβ2 double homozygous mutants...
Pollens of Selected Alergenic Plants and Their Didactic Use in Teaching Biology at High Schools
Pýchová, Adéla ; Skýbová, Jana (advisor) ; Říhová, Dagmar (referee)
7 Abstract The thesis is focused on the pollen of selected allergenic plants. Thesis is structured into two parts., pollination and fertilization , development of the pollen grain , its structure and chemical composition. The end of the theoretical part, dedicated to allergies, is divided into subsections dealing with First, teoretical part describes the flower and its morphology, discusses the pollen grain, stamen anatomical structure immunity and allergies, naming and registration of allergens and cross- pollen allergy . The practical part contains an analysis of curriculum for students of secondary schools. An integral part of the work is a survey of teachers in secondary schools, in which method of questioning was used. The aim of this questioning was to determine the presence of solved issue in terms of representation of pollen and pollen allergens in textbooks for secondary schools , as well as the inclusion of this issue in the official curriculum, under the National Programme for the Development of Education in the Czech Republic. Based on the results of a questionnaire survey of secondary school teachers, teaching materials have been developed in the form of two worksheets for teaching botany and guidance on laboratory exercises in plant biology.
Attractive planting of species of potentially expanding bee pastures for bees
ŠEBESTA, Tomáš
This diploma thesis entitled "Attractiveness of Planting Species with a Potential to Extend Bee Forage for Bees" discusses pollen and nectar plants planted in the Brník municipality in the Central Bohemian Region. The thesis consists of two parts. The theoretical part describes honeybees, bee plants and their pollen- and nectar production ability as well as bee forage from early spring until late autumn so as to reflect the needs of pollinators as best as possible. The practical part uses pollen analysis to microscopically analyse the representation of pollen grains of plants in the honey produced by local bee colonies. Pollen analyses of honey from own bee colonies are compared with that from bee colonies belonging to neighbouring beekeepers.
Androgenesis
Kočová, Helena ; Honys, David (advisor) ; Kocábek, Tomáš (referee)
(anglicky) Androgenesis in the plant kingdom is an interesting phenomenon, in which a new individual is regenerated from male gametophyte. Having gametophytic, i.e. haploid number of chromosomes, these plants are potentially useful in research as well as for the generation of new genotypes. Duplication of their genetic information then results in fully homozygous plants, that can be used for breeding. At the same time, microspores represent a unique system for studying totipotency, cell proliferation, differentiation and embryogenesis. However, in many important crops as well as in some model species, such technology has not yet been efficiently managed. The aim of this thesis is to summarize the knowledge about androgenesis, from the historical context to the latest discoveries, including methods, development, complications and at the end also the possible use of obtained doubled haploid plants. Keywords: androgenesis, male gametophyte, microspore embryogenesis, pollen, totipotency, cell differentiation, stress, organogenesis, haploid

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