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The effect of Hsp70 protein on the infection caused by Potato virus Y
Doričová, Vlasta ; Hýsková, Veronika (advisor) ; Hoffmeisterová, Hana (referee)
Whithin their natural environment, plants are subjected to a combination of stress conditions. Since potential interactions between signal pathways, plants respond to multiple stresses differently from how they do to individual stresses, activating a specific programme. Heat shock proteins (HSP70) overexpressed after heat shock influence the viral infection. On one side HSP70 can participate on refolding of aggregated or partially denaturated proteins, on the other side HSP70 can interact with viral proteins and facilitate propagation of viral replication complexes. In this work the effect of heat shock (42řC, 2. hours) applied before or after the inoculation of plants Nicotiana tabacum L. cv. Petit Havana SR1 with Potato virus Y on viral infection was detected. This effect was studied in two biological experiments. The amount of coat protein of PVYNTN and protein HSP70 were detected simultaneously with the activity assays of Hatch-Slack cycle enzymes, glycosidases and peroxidase. Both experimental approaches (heat shock applied before or after the inoculation by PVYNTN ) enhanced amount of the virus and in the 2nd experiment it accelerated infection development. Immediately after application of heat shock the amount of HSP70 was increased. The enhancement of HSP70 by viral infection occurred...
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The effect of Hsp70 protein on the infection caused by Potato virus Y
Doričová, Vlasta ; Hýsková, Veronika (advisor) ; Hoffmeisterová, Hana (referee)
Whithin their natural environment, plants are subjected to a combination of stress conditions. Since potential interactions between signal pathways, plants respond to multiple stresses differently from how they do to individual stresses, activating a specific programme. Heat shock proteins (HSP70) overexpressed after heat shock influence the viral infection. On one side HSP70 can participate on refolding of aggregated or partially denaturated proteins, on the other side HSP70 can interact with viral proteins and facilitate propagation of viral replication complexes. In this work the effect of heat shock (42řC, 2. hours) applied before or after the inoculation of plants Nicotiana tabacum L. cv. Petit Havana SR1 with Potato virus Y on viral infection was detected. This effect was studied in two biological experiments. The amount of coat protein of PVYNTN and protein HSP70 were detected simultaneously with the activity assays of Hatch-Slack cycle enzymes, glycosidases and peroxidase. Both experimental approaches (heat shock applied before or after the inoculation by PVYNTN ) enhanced amount of the virus and in the 2nd experiment it accelerated infection development. Immediately after application of heat shock the amount of HSP70 was increased. The enhancement of HSP70 by viral infection occurred...
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Influence of sucrose in culture medium on phosphoenolpyruvate carboxylase activity in tobacco leaves
Fiala, Martin ; Ryšlavá, Helena (advisor) ; Hoffmeisterová, Hana (referee)
Plants are under physiological conditions autotrophic organisms that are capable to fix CO2 for the synthesis of carbohydrates. Metabolism of plants may be affected by presence of sucrose in the culture medium. The aim of this study was to determine whether activity of phosphoenolpyruvate carboxylase (EC 4.1.1.31, PEPC) and nitrate reductase (EC 1.7.1.1, NR) were affected by the presence of sucrose in the culture medium. PEPC plays important role in photosynthesis of C4 and CAM plants; in C3 plants PEPC plays an anaplerotic role by replenishing of citric acid cycle intermediates and providing carbon skeletons to support nitrogen assimilation. PEPC activity in plants grown in culture medium with sucrose was about 70 % higher than in plants grown without sucrose. Level of phosphorylation of PEPC was studied by detemnination of PEPC activity after alkaline phosphatase treatment, activation of PEPC by D-glucose-6-phosphate and inhibition of PEPC by L-malate. PEPC activity after dephosphorylation in both groups of plants was decreased at similar level. Also activation of PEPC by D-glucose-6-phosphate and inhibition of PEPC by L-malate was very similar in plants grown with sucrose and without sucrose. NR is a key enzyme in nitrogen fixation. Activity of NR in plants grown with sucrose was about 90 %...
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