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Cell cycle regulation in plants: the role of CDK activatory dephosphorylation at entry into mitosis
Mašková, Petra ; Macháčková, Ivana (advisor) ; Havel, Ladislav (referee) ; Vaňková, Radomíra (referee)
t I I I I I I I I I I I I I I Summary of PhD. thesis Cel1 division representsone of fundamentalattributesof all living creatuÍes.Basic molecular mechanisms operating during cell proliferation seem to be evolutionary conservedamongeukaryotes.The cell cycle is dividedin four subsequentphases;themost regulatoryeventsareconcentratedin Gr/S andGzlM checkpoints. The key regulatory proteins, cyclin-dependentkinases (CDKs), govern the progress throughthe whole cell cycle. Their function is strictly dependenton catalytic cyclin subunits.The correspondingcyclin partnerbinding CDK determinesthe time window of the specific CDlVcyclin complex actionin individual cell cycle phase.To becomefully active, the complex requiresfurtherposttranslationalmodificationincluding activatory phosphorylationanddephosphorylationof theCDK on specificaminoacidresidues. Plant cell cycle, besideswell-conservedmechanismscoÍlmonto all eukaryotes,exhibits other specific mechanismsresultingfrom plant survival strategy.The Gr/S transitionis stronglyaffectedby extemalandinternalsignals,mainlyphytohormonesandmetabolites, reflectingthe elementaryconditionssuitablefor accomplishmentof the whole cell cycle. The centralmoleculerespondingto thesesignalsat Gr/S is D cyclin, whoseexpressionis regulatedby cýokinin and sucrose(Riou-Khamlichi et aI.,...
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The role of cytoskeleton in auxin transport
Kebrlová, Štěpánka ; Petrášek, Jan (advisor) ; Mašková, Petra (referee)
Auxins are a class of plant hormones (phytohormones) with their most frequently endogenously occurring representative indol-3-acetic acid (IAA). Because of their influence on division and elongation of cells, auxins play an important role in many developmental and physiological processes such as embryo development, vascular tissue patterning and tropisms. These effects are often mediated by polar auxin transport, which results in a wide variety of auxin concentrations in cells and entire tissues. Transport of auxin from cell to cell is partly mediated by diffusion, the prevalence of auxin transport is however mediated by auxin carriers located on plasma membrane (PM). Among such carriers belong AUX1/LAX (AUXIN RESISTANT 1/LIKE AUX1) transporter family, which helps with auxin influx and families of PIN-FORMED (PIN) and ABCB/PGP (ATP-binding cassette subfamily B/P-glycoprotein) transporters, which take part in auxin efflux. These proteins are in various degrees dependent on a system of membrane vesicles, trafficking along actin cytoskeleton, which ensures among others cycling of these vesicles among PM and endosomal cell space. Regulation of auxin transport is possible on multiple levels including influencing of gene expression for carrier proteins and regulation of their localization, activity and...
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Mutations in brassinosteroid biosynthetic genes and their effects on plant phenotype
Frimlová, Klára ; Rothová, Olga (advisor) ; Mašková, Petra (referee)
Brassinosteroids are important group of phytohormones, whose presence affects anatomy, morphology and development of plants. They occur in all vegetative and mainly generative organs. Brassinosteroids are biosynthesized via two main paths named early C-6 oxidation pathway and late C- 6 oxidation pathway. Brassinosteroid biosynthesis is catalyzed by enzymes from the group of cytochrome P450. Gene mutations - which affect brassinosteroid biosynthesis - have been studied especially in Arabidopsis thaliana L., Pisum sativum L., Solanum lycopersicum L. and Oryza sativa L. Mutations lead to changes in the composition and amount of brassinosteroids in plants. The reduced content of brassinosteroids is manifested by typical phenotype that includes reduced growth, reduced size of plant organs, and dark green leaves in mutant plants. The mutant phenotype can be reversed by exogenous application of brassinosteroids, which is nevertheless dependent on the concentration of the brassinosteroids used. Higher concentrations of brassinosteroids cause mostly inhibition of root elongation. Keywords: brassinosteroids, biosynthesis, mutant, phenotype
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Visualization of cell structures in leaf cells of Malus domestica as a tool for study of Malus-Venturia inaequalis interactions
Zajícová, Iveta ; Schwarzerová, Kateřina (advisor) ; Mašková, Petra (referee)
Apple scab, the most serious disease of apple is caused by fungal pathogen Venturia inaequalis. Knowledge about the apple response to apple scab attack on the cellular and tissue level is insufficient. For studies of Malus-Venturia interaction on the cellular and tissue level, the establishment of methods for cell structures visualization in apple leaves is necessary. In this work, the experimental plant material grown in vitro and ex vitro was successfully established and the method of apple infection by conidia of V. inaequalis was optimized. Various methods of cell components visualization such as vital staining, in situ immunolocalization, transformation, environmental scanning electron microscopy and confocal microscopy, were tested. Cell structures, such as the cytoskeleton, the cell wall and the cuticle were visualized in apple leaves. Preliminary experiments following specific the changes of cell wall structures induced by V. inaequalis attack were performed. Further, changes of cuticle structure, the first barrier for penetration of pathogen to plant tissues during infection, were observed during the leaf ontogenesis. Powered by TCPDF (www.tcpdf.org)
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Pharmacologically active compounds in hops
Pýchová, Kateřina ; Cvrčková, Fatima (advisor) ; Mašková, Petra (referee)
The hop plant (Humulus lupulus) is used not only in brewing but also in phytopharmacology and phytotherapy. Among the isolated or chemically produced substances used for healing are xanthohumol, 8-prenylnaringenine and α and β-bitter acids. Nowadays, a lot of attention is paid to their effect on humans - especially to their anticancer activity. But there is a lack of information about the importance of these substances for the hop plant itself. Most of the plant secondary metabolites originally serve for protection of the plant against pathogens and herbivores. The selected metabolites are not an exception. The purpose of this work was to summarize the published data about the biological importance of selected hop secondary metabolites and the effects they have on other organisms than plants, with an emphasis on humans.
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Survey of areas of water management sites
Mašková, Petra ; Tuček, Pavel (referee) ; Kalvoda, Petr (advisor)
The aim of this bachelor’s thesis is the creation of the thematic map of a planimetric and altitudinal situation of three water supply sites in the city of Zdar. Part of the map is approximate no dimension plotting of existing engineering networks. The thesis deals with all stages of making thematic map - reconnaissance, construction of the auxiliary survey network, own surveying and processing of obtained data. The survey was performed with using RTK and tacheometry, the map was processed in the Micro Station environment. The final thematic map will be then entered into the owner information system of the related parcels of the firm ZDAS for the administrative and operational purposes.
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Oil economies in the Middle East and North Africa and their development prospects
Mašková, Petra ; Stuchlíková, Zuzana (advisor) ; Cihelková, Eva (referee)
The thesis focuses on the progress of the oil economies in MENA since 90's. Due to the outbreak of unrest in the Arab world, the thesis deals with the political area and causes leading to the Arab Spring. The importance of oil in the world economy and it's discovery in the Middle East and North Africa increased strategic importance of this region. Arab countries have for the past three decades undergone significant social, economic and political transformation and their oil wealth played a major role in this transformation. The first chapter focuses on economic theory dealing with raw materials and their impact on economic growth of countries. The next chapter focuses on presentation of the MENA region. The third chapter deals with the development of four selected countries - Algeria, Egypt, Syria and Libya since 90's, the impact of the global financial crisis on Arab countries and the Arab Spring.
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