National Repository of Grey Literature 15 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Tuber induction in spontaneously tuberizing potato line: the role of saccharides and mobile transcripts
Stupecká, Lenka ; Mašková, Petra (advisor) ; Fischer, Lukáš (referee)
Potato is one of the most important agricultural crops and there is an attempt to increase and improve yields of tubers, among other things, by elucidation of the mechanisms that regulate the process of tuber induction. Potato tuberization is a morphogenetic process in which the tubers are formed from the underground parts of the stem - stolons. The correct timing of this process is controlled by a complex regulatory network and influenced by many internal and external factors. Under favourable conditions, an inductive signal is generated in the leaves and it is transported to the stolon by a "phloem information superhighway" driven by carbohydrates flow. The signal triggers cell division, expansion, and changes in the cell growth orientation in the stolon. The development of tubers is influenced by number of biochemical and morphological processes driven by a regulatory network of genes that are expressed in different parts of plants. This work was focused on Solanum tuberosum, Lada cultivar and its derived D69 mutant line with lacking isoform of manganese-stabilizing protein (MSP), which is so far the only dissimilarity identified under all tested conditions. I aimed to map the processes related to the production of carbohydrates in leaves (photosynthetic characteristics - rate of photosynthesis...
Regulation of floral initiation in woody perennials
Čermák, Vladimír ; Mašková, Petra (advisor) ; Čermák, Vojtěch (referee)
Floral initiation is an important process for temperate woody perennials that affects the subsequent development of the flower. Although this process is well known in annual plants such as Arabidopsis thaliana, not much research has been done in woody plants. This review summarizes the knowledge about mechanisms of flowering induction in woody perennials, compared to the findings in model plants, especially A. thaliana, including factors involved in the regulation of the flowering process. In particular, FT-like genes and TFL1-like genes, which play an important role in the regulation of flowering induction, are discussed in detail. In temperate woody plants the dormancy period follows the floral induction before the floral development. Periodic regulation of this stage is controlled endogenously and, in addition to other factors, it is affected by expression of DAM genes. The genetic mechanisms regulating endodormancy release in woody perennials are similar to vernalization in herbs. Better understanding of processes such as the floral induction and endodormancy release can help us to develop cultivars with a modified flowering time.
Functions of RAB GTPases and SNARE proteins in post-Golgi trafficking pathways in response to abiotic stress in plants
Moulík, Michal ; Hála, Michal (advisor) ; Mašková, Petra (referee)
Plants as sessile organisms are strongly affected by abiotic and biotic stress factors. Thus, they have developed an array of morfological, biochemical and physiological adaptations to reduce the negative effects of these factors. The membrane trafficking, among others, plays very important role in adaptation to abiotic stress. In my bachelor thesis I have focused on two important protein families involved in this trafficking, namely on RAB GTPases and SNARE proteins. In the first part, the phenomenon of stress is characterized and the strategies how plants cope with the effect of stressors are described, especially the production of reactive oxygen species (ROS) and autophagy. Following chapter deals with an introduction to the membrane trafficking in plants. In the rest of the thesis, I characterize RAB GTPases and SNARE proteins and provide contemporary insight in the mechanism of their function. The aim of the key parts of these chapters is to summarize current knowledge of RAB GTPases' and SNARE proteins' functions in post-Golgi trafficking pathways during response to abiotic stressors or secondary oxidative stress. Key words: plants, abiotic stress, membrane trafficking, secretion, endocytosis, vacuole, RAB GTPases, SNARE proteins
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.,...
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...
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
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)
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.

National Repository of Grey Literature : 15 records found   1 - 10next  jump to record:
See also: similar author names
4 Mašková, Pavla
3 Mašková, Pavlína
Interested in being notified about new results for this query?
Subscribe to the RSS feed.