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NADP-dehydrogenases of medicinal plants.
Bartošová, Martina ; Hýsková, Veronika (advisor) ; Kubíčková, Božena (referee)
Medicinal plants usually contain metabolites formed by secondary biosynthetic pathways for example phenylpropanoid and shikimate pathway, which depend on NAPDH availability. In this work total content of phenolic compounds and flavonoids was determined in 10 medicinal plants common for Czech Republic. Activity of enzymes providing NADPH was determined as well. These enzymes were glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49), NADP-isocitrate dehydrogenase (NADP-ICDH, EC 1.1.1.42), NADP-malic enzyme (oxalacetate decarboxylating) (NADP-ME, EC 1.1.1.40). The activity of shikimate dehydrogenase (SDH, EC 1.1.1.25), the main enzyme of shikimate pathway, was also determined. Extraction methods were optimized for each assessment. Applicable source for NADP-dependent enzymes are black radish (Raphanus sativus L. var. niger), garlic (Allium sativum L.) and mint (Mentha piperita L). The highest content of phenolic compounds and flavonoids was determined in sage (Salvia officinalis), lemon balm (Melissa officinalis L.) and Mentha citrata. Extraction with methanol was more effective than extraction with hot water. More extraction methods and studies are necessary for characterization of individual compounds and principals on which they work. Key words: medicinal plants, NADP-dependent enzymes, phenolic...
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The effect of abiotic stress on cucumber plants (Cucumis sativa L.)
Plisková, Veronika ; Hýsková, Veronika (advisor) ; Müller, Karel (referee)
The exposure of plants to high salt concentrations causes accumulation of sodium ions. This leads to the inability of the plants to uptake water, a disturbance of ion homeostasis, a decrease in photosynthesis and oxidative stress. As a result of the salt stress, the availability of NADPH decreases. The adaptation to the concentrations of salt depends on plant's ability to compensate for the decreased availability of NADPH, which can be further used in antioxidative cycles and the synthesis of antioxidative compounds and osmoprotectants. In this work, the reduction of relative water content, a decrease in the Rubisco enzyme activity, an increase of Hsp70 in the leaves and an increase in the accumulation of sodium ions was shown in cucumber plants (Cucumis sativa L. convar. Jogger F1) exposed to salt stress (100 mM NaCl). As a consequence of salt stress, an increase in the activity of NADPH providing enzymes was found. Particularly on the second and third day of salt stress, an increase in the activity (up to 270 %) of: NADP-isocitrate dehydrogenase, glucose-6-phosphate dehydrogenase, NADP-malic enzyme, non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase in leaves was detected. The activity of less abundant NADP-dehydrogenases (glucose 1-dehydrogenase, gluconate 2-dehydrogenase, galactose...
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The effect of heat shock stress on enzyme activities in plants.
Doričová, Vlasta ; Hýsková, Veronika (advisor) ; Liberda, Jiří (referee)
Heat stress is one of abiotic stress factors, which fundamentally influences the growth and development of plants. Plants response to heat stress by series of cell and metabolic changes, the specificity of heat stress is synthesis of molecular chaperons, called heat- shock proteins (HSP). The influence of heat shock (in the form of 1 hour application of 40řC from 20řC) on the activity of NADP-dependent enzymes, enzymes of Hatch-Slack cycle, glycosidases and the activity of peroxidase in tobacco plants (Nicotiana tabacum L. cv. Petit Havana SR1) was studied in this work. Since HSP are involved in proper folding of immature, misfolded or partly denaturated proteins, in degradation of denaturated proteins and in induction of thermotolerance of plants, the aim of this work was to find out, if the activity of studied enzymes will be maintained or modulated within the plant defense response. The highest amount of HSP70 detected immunochemically together with higher activities of NADP-malic enzyme, phosphoenolpyruvate carboxylase, β-hexosaminidase and α- mannosidase compared to control plants was found 1 hour after application of heat shock. Peroxidase activity was most increased 1 day after HS compared to controls. Using native electrophoresis the differences in isoform content between control and...
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NADP-dehydrogenases of medicinal plants.
Bartošová, Martina ; Hýsková, Veronika (advisor) ; Kubíčková, Božena (referee)
Medicinal plants usually contain metabolites formed by secondary biosynthetic pathways for example phenylpropanoid and shikimate pathway, which depend on NAPDH availability. In this work total content of phenolic compounds and flavonoids was determined in 10 medicinal plants common for Czech Republic. Activity of enzymes providing NADPH was determined as well. These enzymes were glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49), NADP-isocitrate dehydrogenase (NADP-ICDH, EC 1.1.1.42), NADP-malic enzyme (oxalacetate decarboxylating) (NADP-ME, EC 1.1.1.40). The activity of shikimate dehydrogenase (SDH, EC 1.1.1.25), the main enzyme of shikimate pathway, was also determined. Extraction methods were optimized for each assessment. Applicable source for NADP-dependent enzymes are black radish (Raphanus sativus L. var. niger), garlic (Allium sativum L.) and mint (Mentha piperita L). The highest content of phenolic compounds and flavonoids was determined in sage (Salvia officinalis), lemon balm (Melissa officinalis L.) and Mentha citrata. Extraction with methanol was more effective than extraction with hot water. More extraction methods and studies are necessary for characterization of individual compounds and principals on which they work. Key words: medicinal plants, NADP-dependent enzymes, phenolic...
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