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The role of carotenoids in higher plants ontogenesis and adaptation to stress conditions
Haisel, Daniel ; Pospíšilová, Jana (advisor) ; Hnilička, František (referee) ; Hronková, Marie (referee)
t' fi I tl I _ l f] I I 'l I _ l 'l I _ l 'l I _ l 't I -l 1I ----l I- - l _:t -t I I I 5.Conclusions On thebasisof resultsobtainedandpresentedin this Ph.D.thesis,we cananswerthequestion settingin "Aimsoo: 1.During ontogenyof plantsgrownin vilro, thecontentandfunctionof carotenoidschanged in dependenceon cultivationconditions(inadiance,presenceof sucrosein medium, COz concentration).These cultivationconditionsaffectedcarotenoidpatternalso after ex vitro transfer. 2. Protectivefunctionof carotenoidswas positively affectedby sucrosein medium under higherirradiancebutnotunderlow irradiance. 3. Higherirradiancein combinationwith sucrosein cultivationmediumhadpositiveeffecton carotenoidcontentsin beginningof exvitro acclimation. 4. Changes in carotenoidscontentand function ďter ex vitro transfer were dependenton previous in vitro cultivation as well as on conditionsduring ex vitro growth.Very important were irradianceand COz concentration.The shift of function of carotenoidsfrom light- harvestingto protectiveenabledthatphotoinhibitionwasnotobservedafterexvitro transfer. 5. The contentof xanthophyllcycle pigmentsandtheirde-epoxidationstateincreasedduring waterstress.Also in theseexperimentscarotenoidsprotectedplantsagainstphotoinhibition damage. 6. Biosynthesisof carotenoidsincludingxanthophyllcycle...
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Using of Analytical Methods for Study of Adaptation Mechanisms of Festuca Rubra L. Plant
Paučová, Michaela ; Haisel, Daniel (advisor) ; Hnilička, František (referee)
Due to abiotic stress factors, such as excess of electromagnetic radiation, high and low temperature, drought, moisture or salinity, the reactive oxygen species (ROS) in living organisms which have a negative impact on the proper functioning of vital organs, metabolic pathways and ultimately, existence, are formed. In the case of a plant, this is in particular a limited activity of the photosynthetic apparatus which can lead to the death of the plant. All of analysis were preceded by the collection of Festuca rubra L. samples from different locations in the south-western part of Norway. The locations were different in their temperature (6,5; 9,5 and 10,5řC) and moisture (600, 1200, 2000 and 2700 mm). Then all samples were cultivated in four climaboxes where combinations of four "extreme" temperatures and moistures (moist/cold, moist/warm, dry/cold and dry/warm) were set. Experimentally this work was focused on the extraction of ascorbate peroxidase as an antioxidant enzyme, phenolic substances and plant pigments present in Red Fescue (Festuca rubra L.) as a model organism. The activity of ascorbate peroxidase was quantitatively determined by spectrophotometric reduction of nitrobluetetrazolium, the phenolic content was evaluated spectrophotometrically by the Folin-Ciocalteau reagent and the plant pigments...
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Enhanced plant tolerance after ABA application
Pospíšilová, Jana ; Synková, Helena ; Baťková, Petra ; Haisel, Daniel ; Pešek, Bedřich
Critical period during micropropagation is often ex vitro transfer. The aim of this research was to determine whether exogenous abscisic acid (ABA) applied immediately after ex vitro transfer of in vitro grown tobacco regenerants can not only decrease transpiration rate and so partially eliminate their wilting but also ameliorate photoinhibition and oxidative stress. After ABA application, ABA content in tobacco leaves increased considerably, stomatal conductance and transpiration rate decreased more than in control plants and their wilting was limited. Chlorophyll and -carotene contents were higher in these plants, but the content of xanthophyll cycle pigments was not increased. However, the degree of xanthophyll cycle pigments deepoxidation was decreased what also suggested less stress in these plants. Applied ABA stimulated activities of some antioxidative enzymes but not immediately after ex vitro transfer.
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