|
|
External conditions, seed characteristics and other factors affecting seed germination of alpine species
Veselá, Andrea ; Münzbergová, Zuzana (advisor) ; Jiménez-Alfaro, Borja (referee) ; Doležal, Jiří (referee)
Germination is the most critical and vulnerable stage in the life cycle of many plants and it directly influences the regeneration potential of populations and thus long-term survival of species. Species germination is affected by external conditions such as light, temperature and moisture acting both during germination (target conditions) and on maternal plants during their life (original conditions). Target and original conditions can interact and affect seed germination as well. The strong temperature and moisture control of seed germination suggests that species recruitment rates and success may be strongly impacted by ongoing climatic changes. Simultaneously, species germination is influenced by characteristics of the seeds themselves, such as, seed mass or seed nutrient content, which can be affected by external climatic conditions as well. This thesis aimed to i) investigate the effect of temperature and moisture acting separately and in interaction as target conditions, original conditions and as interaction between target and original conditions on germination behaviour of alpine species; ii) study effect of seed origin on seed mass and seed nutrient content and their effect on germination; iii) explore how abundance of species is affected by germination behaviour in central European...
|
|
|
External conditions, seed characteristics and other factors affecting seed germination of alpine species
Veselá, Andrea ; Münzbergová, Zuzana (advisor) ; Jiménez-Alfaro, Borja (referee) ; Doležal, Jiří (referee)
Germination is the most critical and vulnerable stage in the life cycle of many plants and it directly influences the regeneration potential of populations and thus long-term survival of species. Species germination is affected by external conditions such as light, temperature and moisture acting both during germination (target conditions) and on maternal plants during their life (original conditions). Target and original conditions can interact and affect seed germination as well. The strong temperature and moisture control of seed germination suggests that species recruitment rates and success may be strongly impacted by ongoing climatic changes. Simultaneously, species germination is influenced by characteristics of the seeds themselves, such as, seed mass or seed nutrient content, which can be affected by external climatic conditions as well. This thesis aimed to i) investigate the effect of temperature and moisture acting separately and in interaction as target conditions, original conditions and as interaction between target and original conditions on germination behaviour of alpine species; ii) study effect of seed origin on seed mass and seed nutrient content and their effect on germination; iii) explore how abundance of species is affected by germination behaviour in central European...
|
|
|
Molecular mechanism of hydrogen sulfide action during meiotic maturation of porcine oocytes
Veselá, Andrea ; Hošková, Kristýna (advisor) ; Tomáš, Tomáš (referee)
At present reproductive biotechnology methods are on the rise, but their development and application in the broader management of reproduction is dependent on obtaining a sufficient number of quality oocytes cultured in vitro. The prerequisite for this requirement is the creation of the optimal conditions in the course of culturing oocytes.
Understanding and knowledge of the processes that occur in oocyte during maturation is an important and necessary condition for optimizing the process of culturing oocytes in vitro and gaining a sufficient number of good quality oocytes in metaphase II of meiotic division. A large number of mechanisms that affect and control oocyte maturation are known, however it cannot be claimed that this process has been fully explained and studied. One factor which has a potential role in the regulation of meiotic maturation of oocytes is gasotransmitter hydrogen sulfide (H2S), a critical signaling molecule of endogenous origin.
The study of H2S led to the hypothesis that H2S actively influences the course of meiotic maturation of pig oocytes by regulating key signaling cascades. The aim of this work was to determine the involvement of H2S in the regulation of the MEK1-MAPK signaling cascade, responsible for the initiation and progress of the meiotic maturation of oocytes and the MEK1-PARP-1 cascade as signaling that supports cell viability. For this purpose, pig oocytes cultured in modified media were used, supplemented with a specific combination of enzyme inhibitors (3Ki) or in a culture medium with donor H2S. The ocytes were then subjected to immunocytochemistry staining, fluorescence microscopy and image analysis.
The results show that H2S is involved in the regulation of meiotic maturation. It confirmed the hypothesis of the endogenous production of H2S in the course of the meiotic maturation of pig oocytes and the influence of the MAPK signaling cascade. Based on the results, it is however likely that the MEK1-PARP-1 signaling cascade is not affected by H2S, unlike MAPK signaling, comprising the mentioned MEK1 as superior kinase. MAPK kinase activity is significantly lower in oocytes after treatment 3Ki. Further experiments are for a detailed understanding of these regulatory pathways and for the proper verification of the mechanism of the effects of H2S necessary, in particular for a full understanding of the target control factors by the post-translational modification of S-sulfhydration.
|
|
| |
guest ::
RSS feed.