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The role of small RNAs in transgenerational plant stress memory
Jaklová, Veronika ; Marková, Hana (advisor) ; Lipavská, Helena (referee)
Plants are constantly affected by various abiotic and biotic stresses, which cause a whole range of reactions.The resultcanbe increasedplantresistance tovariousstressfactorssuchasherbivoryattack or lack of water. Additionally, this resistance can also be passed on to subsequent generations through epigeneticmechanisms.Small RNAsservingas signaling moleculesof the plant's rapid response tostress can play a large part in the formationof intergenerationalandmultigenerationalstressmemory.MiRNAs are mainly regulators of gene expression,throughtheirinhibitory and degradative activitiesthey control the transcription of genes and the translation of a large number of proteins. SiRNAs could participate in the transfer of transcriptional memory through the mechanism of RNA-directed DNA methylation (RdDM). DNA methylation and histone modifications together act as chromatin marks that can be epigeneticallytransferredtosubsequentgenerations.Basedonthis,plants derivedfromstressedparent plants show large changes in gene expression compared to plants with non-stressed parents. These changesthenpersistfor varyinglengthsof time,dependingon whethergene expressionisagain induced bythe stressfactoror not.Interestinunderstandingthe mechanismsof transgenerationalstressmemory has recently grown considerably, and this...
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Effect of chromatin on the repair of double-strand DNA breaks after cleavage by CRISPR/Cas and other programmable nucleases in plants
Trojan, Jakub ; Přibylová, Adéla (advisor) ; Procházková, Klára (referee)
Plants are highly resistant to ionizing radiation, also thanks to a high-quality repair system for repairing double-stranded breaks. Double-strand breaks in plants are repaired by four repair pathways. Most often, double-strand breaks are repaired by non-homologous end joining (NHEJ), which joins the broken ends without further processing. More accurate but slower and more complex is repair through homologous recombination (HR), which repairs the break using a homologous sequence. HR repair takes place preferentially in a region with active transcription and during the S and G2 phases of the cell cycle. Alternatively, repair further proceeds through single-strand annealing (SSA) or Theta mediated end joining (TMEJ). Both pathways are based on short homology between the overlapping ends of the double-strand break. An often neglected part of repairs is the overcoming of repressive chromatin, which protects the genome from DNA damage and prevents access of nucleases but also acts as a barrier for repair proteins. This work summarizes the current knowledge about DNA repair in plants. Furthermore, describe the influence of chromatin not only on the repair but also on the activity of programmable nucleases used in genetic engineering, such as zinc finger nucleases (ZFNs), transcription activator-like...
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CITES plants in cosmetic products
JAKUBCOVÁ, Claudia
This thesis deals with the properties of endangered plant species listed in CITES Appendices that are contained in cosmetic products on the Czech market and the characteristics of these products. The attitude and responsibility of companies towards environmental protection issues and the evaluation of these cosmetic products by users were investigated by questionnaires. A total of 20 species were found in 90 cosmetic products, of which 12 representatives were from the family of Orchideaceae, two species of cacti (Selenicereus grandiflorus, Opuntia ficus-indica), ginseng (Panax ginseng, Araliacae), Aloe ferox (Asphodelaceae), Euphorbia antisyphilitica (Euphorbiaceae), Aniba rosodora (Lauraceae), Aquilaria malaccensis (Thymelleaceae), Cyathea medullaris (Cyatheaceae). No cases of collection in the wild were found. All the evidence shows that the plants used in cosmetics are cultivated and therefore the CITES Convention is not violated. Users were satisfied with the cosmetic products.
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Proposal of project based education on the topic of air-conditioning function of vegetation in the landscape
ŽEJDL, Matěj
As part of this work, the role of the regional vegetation in the water cycle was designed in the project of education. The project was made in a try of the praxis. A part of the education is measuring air temperature and the relative air humidity in the different habitats. Due to this measuring primary school students can see differences between habitats and they can think about the meaning of the project education in the role of the differences in the vegetation and in which way flora is influencing the water. The work is focused on the research of the meteorological and biological conditions suitable for education project management. Work also briefly sums the role of respondents in the Biology lessons and their knowledge of the examined topics made during the lectures. The finding of the primary school student's knowledge was done with the use of questionnaire.
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Plants as model organisms in inquiry science education in primary education
JINDROVÁ, Aneta
Research-oriented teaching is an attractive way of teching (not only) science subjects. At the first stage of primary school, it is an opportunity for developing students' research abilities. Plants are a suitable subject with which simple experiments, observations and research activities can be performed. The aim of the work is not only to find the possibility of using plant material in students' science research during teaching, but also to evaluate how research activities are accepted by students, how they are able to solve problems and how creative they are in solving research tasks. The work should show the possibilities of combining standard tasks based on plant observation with tasks based on different levels of research activity. The diploma thesis is divided into a theoretical and a practical part. I approached this thesis in four steps. In the first step the curriculum and content of selected textbooks are analyzed with a focus on the issue of learning about living nature, in the second step the educational offer is presented, in the next step the proposed educational offer is verified with simultaneous monitoring and analysis of students 'research tasks and pupils' creativity. In the last step, the results of the survey are evaluated and the obtained data are interpreted. The diploma was drawn up as part of a project GAJU 123/2019/S.
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The use of Natural Materials in Primary School Education
BARTOŠOVÁ, Martina
The theme of this diploma thesis is Natural materials in the subject of Craft at primary school (at the first level of the elementary village school). The aims and tasks of the diploma thesis are defined in the introduction. The theoretical part is devoted to concepts, goals and output competences in technical and environmental education at the first level. It deals with the description of well-known and lesser-known nature materials and the characteristics of various natural techniques when working with natural materials. The description of the elementary school in the village of Malonty is the integral part of the theoretical text. In the practical part, ten didactic themes for working with natural materials are proposed. Some of them were realized in practice and their effectiveness was verified through questionnaires for children.
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USE OF COMPLEX EXTRACTS FROM PLANT AND MICROORGANISMS IN FOODS AND COSMETICS
Uhlířová, Renata ; Kovalčík, Adriána (referee) ; Vorlová, Lenka (referee) ; Márová, Ivana (advisor)
The presented doctoral thesis is focused on optimalization of preparation of extracts of various origin (plant and microbial). The influence of extraction agent, disintegration of microbial cells as well as special techniques for enhancement of extraction process effectiveness (ultrasound and microwaves) were monitored. As part of the characterization, considering the source material, the composition of the prepared extracts was analyzed both spectrophotometrically and using liquid and gas chromatography. The most suitable extraction procedure varies depending on the type of material. For herbal samples, the highest content of active substances was achieved when the extraction facilitated by microwaves was used. Contrarily, the optimal method for cyanobacteria is the traditional extraction method, which is carried out for 24 hours at laboratory temperature. The most suitable method for extracting the active substances from yeast was a combination of DMSO, ethanol and hexane. Further, the effect of extracts on microbial cultures of bacteria (E. coli, S. epidermidis, C. acnes) and yeast (C. glabrata) was observed. For cytotoxicity evaluation MTT and LDH assays were performed on HaCaT and Caco2 human cell lines. The antimicrobial tests have demonstrated the antimicrobial, antibacterial and antifungal effect of a numerous extracts, especially the essential oils of Lavandula angustifolia and Mentha piperita. On the other hand, the cytotoxicity tests showed that the most of the extracts were safe for the use in the food industry and cosmetics within a range of up to 10% by volume. To improve stability, the prepared extracts were enclosed into liposomal particles enriched with PHB polymer (0–100%). Using a ZeteSizer NanoZS device, the particles' size, polydispersity index, and colloidal stability were assessed. The cryoTEM was used to examine the particle´s morphology. Liposomes and liposomes with the addition of 20 % PHB (PHB20) were evaluated as the most suitable particles for encapsulation of the prepared extracts. Excellent stability and high encapsulation efficiency were displayed by the produced particles. Genotoxicity testing with SOS chromotest on the model organism E. coli did not reveal any genotoxic effects. As an alternative method to achieve stabilization of active substances, nanofibers from PHB were prepared by three different techniques and gelatin nanofibers by electrospinning. The fibers were monitored for their diameter, uniformity, distribution on the collector using SEM and the gradual release of active substances from the fiber structure. The evaluations revealed that the forcespinning and electrospinning techniques were the most appropriate for further investigation. A continuous release of active ingredients was achieved by incorporating extracts into nanofibers. Several applications of prepared materials in the food industry and cosmetics were designed and developed as part of this work. The base emulsion's stability and general qualities were improved when green coffee and carotenogenic yeast extracts were added. The usage of emulsions containing coffee and yeast extracts would be suitable as sunscreens, and after the addition of Spirulina extract, as day or night anti-wrinkle creams. Energy drinks of the new type based on coffee with the addition of encapsulated plant extracts enable gradual release of caffeine and antioxidants during digestion.
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Heat-shock proteins and plant tolerance against high temperature stress
Ott, Kristián ; Hála, Michal (advisor) ; Konrádová, Hana (referee)
In context with ongoing climate change, the average temperature is still rising. This is a problem mainly for agriculture and production of groceries, because plants generally have difficulties when coping with ambient temperature higher than 40 řC. If there would be continuing trend in decrease of global food production, it could cause problems with feeding still growing world population. Organisms in general developed many mechanisms of stress adaptation. One of these evolutionary adaptions to high temperature stress is production of heat shock proteins (HSPs). HSPs are very conserved family of proteins present in both prokaryotes and eukaryotes. This thesis summarizes present knowledge about the HSPs and their function (not only) during the high temperature stress in plants, but some of the information presented in this thesis were obtained also from other organisms. The thesis starts with general introduction to the high temperature stress and how plants can sense the ambient temperature. Next is general mechanism of induction of HSPs and their classification, structure, and mechanism of action. The possibility of future use of HSPs in agriculture and medicine is opened in last chapter.
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Electrophoretic determination of oxidized and reduced form of glutathion in plant material
Durychová, Eva ; Křížek, Tomáš (advisor) ; Kubíčková, Anna (referee)
This work is based on a previously published method for the determination of twenty proteinogenic amino acids by capillary electrophoresis with contactless conductivity detection and deals with possibility of its use for the determination of oxidized (GSSG) and reduced (GSH) forms of glutathione with amino acids. The theoretical part firstly deals with brief introduction of the properties and importance of glutathione and its protection against autooxidation, especially by alkylation with N-ethylmaleimide (NEM), which binds to GSH to form its alkylated form (GSH-NEM). Then, a brief summary of the available methods for determination of glutathione is given, with a focus on the already developed capillary zone electrophoresis methods. Finally, it briefly presents the electrophoretic method for the determination of twenty proteinogenic amino acids on which this work is based. In the experimental part, the integration of the determination of both forms of glutathione into the method for the determination of proteinogenic amino acids is presented. First, a simplified, less time consuming method was tested in shorter 50.0 cm capillary without hydroxyethylcellulose, where both forms of glutathione were separated at baseline within 10 minutes. Relative standard deviations of peak areas (GSH 2.1%; GSSG...
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