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Řízkování vybraných kultivarů konopí v řízených podmínkách
Jakešová, Kristýna
The work subject is a general description of hemp (Cannabis sativa) and research on the practice of cutting, which greatly affects the production of hemp. The object of the research was to determine the effect of auxins in certain proportions and concentrations on rooting of cuttings of two varieties (Bedrocan and Bedrolite), which were imported from the Dutch company Bedrocan. We used auxins as indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA).
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Regulácia vyrastania kotylárnych pupeňov hrachu
Kucsera, Attila
This work was aimed to achieve more details in regulation of cotyledonary bud outgrowth of pea plants (Pisum sativum L.). Plants were studied after decapitation of the apex and removal of cotyledons and their subsequent substitution with agar gels containing different susbstances. Experiments were perform in light and dark conditions. The obtained results proved that auxin could regulate outgrowth of pea cotyledonary buds. Furthermore, sucrose showed partly inhibitory effect on bud outgrowth. This inhibitory effect was pronounced if plants were cultivated in dark. Next experiments showed that cotyledons could regulate apical dominance depending on light or dark conditions.
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Vplyv kyseliny jasmónovej na rast a vývoj rastlín v odpovedi na zmenené hladiny endogénnych cytokinínov
Perašínová, Nikola
Plant hormones act as messengers of intracellular and extracellular signals in the plant cell that regulate various developmental processes. The main plant hormones participating in intracellular and extracellular signal transduction pathways are, among the others, cytokinins (CK) and jasmonic acid (JA). The role of both hormones in plant development is well-known, whereas their mutual interactions remain rudimentary. In this thesis, we have found that elevated JA levels contribute to enhancing CK sensing by plants. On the other hand, the high levels of CK were found to stimulate expression of transcription factors that play a key role in JA signaling pathway. Our results suggest interesting interaction network of two plant hormones, which participate in abiotic and biotic stress responses. These findings offer a novel universal method for the sustainable agriculture that raises demands for stress-tolerant crop species.
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Fyziologické aspekty vegetativního množení dřevin řízkováním
Kohoutková, Petra
My work deals with physiological aspects of vegetative multiplication of species through section. On the basis of reading and studying of twenty-one specialised publications and thirteen electronic articles I tried to describe the core of impacts influencing the plants. I was concerned with stress factors, ways of multiplication of plants and using of growth stimulants. In my work I especially focus on the best way of multiplication of plants through section and on function of phytohormones on cuttings. Plants can influence production of stress factors impacting their progression.
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The characterisation of organ-specific phytohormone responses to nutrient deficiency and biotic stress
Kramná, Barbara ; Vaňková, Radomíra (advisor) ; Hronková, Marie (referee) ; Plíhalová, Lucie (referee)
Abiotic and biotic stresses lead to crop yield losses and ultimately negatively affect agriculture production. Elucidation of the mechanisms of plant stress responses and their regulation could help to understand plant defence and improve stress tolerance. Phytohormones stand behind both plant growth and developmental changes as well as stress signalling. This thesis summarises the results published in two articles focused on phytohormone dynamics in response to abiotic and biotic stresses, namely phosphate shortage and Plasmodiophora brassicae infection. A review article focuses in depth on strigolactones as master regulators of phosphate deficiency responses. The main emphasis is put on organ-specific reactions and exogenous phytohormone treatment with the potential to convey stress tolerance. In the case of phosphate shortage, the universal reaction in all organs was a decrease in active cytokinin trans-zeatin and gibberellin GA4 with a concurrent elevation of abscisic acid. Also, the high- affinity phosphate transporters (PHT1;4 and PHT1;7) exhibited increased gene expression within the whole plant. Shoot apical meristems showed numerous changes in gene expression and were the most affected organ during the lack of phosphate. Only in roots, we observed a substantial elevation of low active...
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Exodermis differentiation under nutrient deficiency, effects of phytohormones.
Namyslov, Jiří ; Tylová, Edita (advisor) ; Martinka, Michal (referee)
Apoplastic barriers (exodermis and endodermis) control free movement of substances by apoplast, which is achieved by specific cell wall modifications. Differentiation of these barriers is to some extent variable. It has been demonstrated many times that the differentiation of root apoplastic barriers is strongly influenced by unfavourable environmental conditions. Many stress factors accelerate the deposition of apoplastic barriers. This work deals with the relationship between availability of nutrients and development of root barriers and mechanisms of coordination of developmental processes in roots, including the involvement of auxin and other phytohormones in the coordination of these processes. The exodermis developmental plasticity is followed in maize (Zea mays L.) under conditions of various nutrient deficiencies. The most important results are presented by anatomical analysis, which shows a significant acceleration of exodermis and endodermis differentiation in the N and P deficiency on the contrary, the slowing of differentiation in the absence of Fe and K. This effect is apparently a result of systemic rather than local root system responses because it was not observed with localized deficiency. This thesis also test the influence of some phytohormones on the development of apoplastic...
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Characterization of the role of cytokinins and abscisic acid during abiotic stress response
Přerostová, Sylva ; Vaňková, Radomíra (advisor) ; Havel, Ladislav (referee) ; Doležal, Karel (referee)
Abiotic stresses significantly reduce crop yield, causing serious problems in agriculture. Understanding the mechanisms of plant stress responses could contribute to the improvement of their stress tolerance. Phytohormones play an important role in plant stress defence as well as in regulation of growth and development. This thesis summarizes the results published in four articles focused on the evaluation of the effects of phytohormones during abiotic stresses, namely salinity, drought, ZnO nanoparticle treatment and cold stress. The main emphasis is put on abscisic acid as the key regulator of water status and stress defence, and on cytokinins, which regulate plant growth and stabilize photosynthetic machinery. Cytokinins act antagonistically to abscisic acid. Our results showed that abscisic acid is a general abiotic stress response regulator. Stress- tolerant plants (halophyte Thellungiella salsuginea or winter line of einkorn wheat Triticum monococcum) had a higher basal level of this hormone, especially in shoot meristematic tissues (apices, crowns), than stress-sensitive plants. Stress-tolerant plants reacted faster and in a more flexible way to stress. Active cytokinins were negatively affected by stress, which was associated with growth suppression. The drought stress study showed that...
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Aplikace růstových regulátorů pro multiplikaci Vitis vinifera L. v podmínkách in vitro
Mančíková, Simona
The experiment was done at Faculty of Horticulture in Lednice, at the Mendeleum-Institute of genetics. The plant materil was obtained from the technical isolation in Lednice. Four selected grape varieties ('MT' 25/7, 20/52'PM','CR2' 1/48,'K 5BB') as primary culture and multiplied in selected media. All varieties were grown at the same temperature and light conditions. MS medium combined with BA (0.7 mg.l-1), IAA (0.1 mg.l-1) was chosen for the primary culture. The pH was adjusted to 5.8. After the establishment of primary cultures, only the variety 'CR 2' 1/48 survived. In the other varieties ('MT' 07/25, 20/52 and 'PM''K 5BB') infection by fungal and bacterial infections, hyperhydratation, no proliferation of shoots and necrosed individual segments were observed. Variety'CR2' was (after the establishment of primary cultures) multiplied onfive media; DKW combination of BA (0.6 mg.l-1), IBA (0.01 mg.l-1), MS in combination with BA (3.0 mg.l-1), NAA (0, 2 mg.l-1), C2D combination of BA (1.5 mg.l-1), MS enriched by BA (1.5 mg.l-1), IBA (1 0 mg.l-1), and LQ combination of BA (0.4 mg.l-1) and NAA (0.01 mg.l-1). Individual media were evaluated separately with the calculation multiplier of 4 passage. C0 medium was evaluated as the most suitable medium for in vitro grapevine multiplication . The lowest number of new formed shoots and also the worst results were observed on C1 medium. The results of the thesis evaluaete the health condition of plants and the multiplication factor on different media. New formed shoots during the ever single passaging was evaluated as well.
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Cytokinines and their role in plant cell division, with accent on G2/M transition
Prášilová, Jana ; Ševčíková, Hana (advisor) ; Bíšová, Kateřina (referee)
The eukaryotic cell cycle is well understood mainly in yeasts and animals. Basic regulatory mechanisms, with cyclin-dependent kinases (CDKs) playing crucial roles, are similar in all eukaryotes including plants. CDKs operate mainly at the key cell cycle checkpoints, G1/S and G2/M. Phosphorylation and dephosphorylation of CDKs by kinases and phosphatases have both negative and positive effect. Negative regulator at the G2/M transition is WEE1 kinase which phosphorylates conserved amino acid residues T14 and Y15 of CDK. Phosphatase CDC25 removes this inhibitory phosphate in yeasts and animals and forces cells into mitosis. Plant cell cycle exhibits remarkable differences. Importantly, it is controlled by phytohormones, and some key points of regulation remain obscure - a functional plant homologue of yeast CDC25 phosphatase has not been found in plants yet though Y15 inhibitory phosphorylation by WEE1 kinase blocks mitosis entry in plants as well. Thus, the regulatory mechanism of G2/M transition in plant cells is still to be found. Phytohormones play a key role, not only in the plant cell cycle, but in whole plant development. Interplay between the two groups of phytohormones: auxins and cytokinins, is crucial. Especially cytokinins significantly influence the regulation of G2/M checkpoint. It is...
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Regulation of phosphate uptake by strigolactones
Balín, Michal ; Vaňková, Radomíra (advisor) ; Tylová, Edita (referee)
This Bachelor thesis is focused on the reactions of plants to low levels of available phosphorus, which is essential element for plant nutrition. In the context of plant stress, plant hormones strigolactones play very important role. Strigolactones influence growth and development of the whole plant. Biosynthesis of strigolactones increases under phosphate deficiency. This thesis consists of three parts. The first part is concentrated on phosphorus, its compounds and its availability in the environment. The second part is mainly dedicated to phosphate stress - its sensing by plants, their adaptations to stress and local as well as long distance signalling. Attention is also paid to phytohormones, namely auxins, cytokinins, gibberellins, ethylene, abscisic acid and other signal molecules, like sucrose, the phosphate molecule itself and microRNAs. The third part is focused mainly on the structure, biosynthesis, signal transduction and the mode of action of strigolactones during phosphate stress. Keywords: phosphate, deficiency, strigolactone, phytohormones, stress
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