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The effect of biotic stress on the metabolism of saccharides in tobacco plants (Nicotiana tabacum L.)
Kloudová, Kateřina ; Ryšlavá, Helena (advisor) ; Tichá, Marie (referee)
Plants have developed a number of ways how to minimise negative influence of the environment. As a consequence of stress action, plants carbohydrate metabolism is quite often influenced, esp. on the level of expression and activities of different enzymes and also several metabolites concentration. One of key enzymes of carbohydrate metabolism is invertase. The aim of this work was to find out, whether the activity of its isoforms (cytoplasmic, vacuolar and extracellular) in tobacco plants is influenced by Potato virus Y (PVY). It was shown, that activity of cytoplasmic invertase was not affected, but the activity of vacuolar and extracellular isoform was enhanced during potyviral infection. Hence, it is likely, that vacuolar and extracellular invertases are related to plant antiviral defence. The effect of PVY on other enzymes of carbohydrate metabolism and several metabolites content was studied. Activity of α-amylase and phosphorylase, starch-degrading enzymes, was strongly enhanced during potyviral infection. That is probably how plant cells get glucose, which is a key source of energy and metabolites for biosynthesis of different compounds. It may also serve as a signal molecule. Activity of other hydrolytic enzymes, β-glucosidase and β-hexosaminidase, was also slightly increased. There was no...
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Perpectives of crude oil market developement
Vosková, Michala ; Lukáš, Zdeněk (advisor) ; Kalínská, Emílie (referee)
Crude oil is an important commodity of world trade and it has become an essential part of everyday life. It is a necessary condition of economic growth, which in the current situation of economic boom of China, India and other developing countries entails an economically, ecologically, socially and geopolitically unsustainable problem. The turbulent sequence of past events on the crude oil market only foreshadows the future development that is going to occure after achieving the crude oil production peak. The following irreversible changes will be more revolutionary than evolutional. The era of cheap oil will parish and the 21st century is going to be distinguished by fights for energy and resources. This is one of the reasons why many renowned institutions and organisations are concerned with these questions, trying to predict future scenarios and find feasible solutions. The world needs secure, renewable and environmentally friendly energy sources, however crude oil is unfortunately none of them. Radical transition from crude oil economy to a clean alternative one, that is probably the most suitable solution to current situation, will require engagement of governments, organisations and individuals as well. It is an inevitable step of preserving the world for humanity and the coming generations. Crude oil market perspectives are quite well foreseeable for the coming decades, questionable remains only the proper solution of the rising problems and action of taking the correct steps in the right direction.
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