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Dynamics of carbon and phosphorus flows in arbuscular mycorrhizal symbiosis
Konvalinková, Tereza ; Jansa, Jan (advisor) ; Baláž, Milan (referee) ; Kolaříková, Zuzana (referee)
Dynamics of carbon and phosphorus flows in arbuscular mycorrhizal symbiosis Mgr. Tereza Konvalinková (doctoral thesis) Abstract Arbuscular mycorrhizal fungi (AMF) are widespread and highly specialized root symbionts, which gain all of their carbon (C) from the hosts, supplying plants with mineral nutrients (particularly with phosphorus, P) in return. This thesis focuses on the size and flexibility of C and P flows in arbuscular mycorrhiza in relation to environmental conditions, in particular to light and P availability. The indications that the symbiotic flows are regulated actively by both partners are discussed. The main findings are presented as a compilation of separate scientific works (two research articles, one review and one book section). A glasshouse experiment has shown that both mycorrhizal benefits and mycorrhizal colonization of medic (Medicago truncatula) by an AMF species (R. irregularis) decline along the gradient of decreasing light intensity. Interestingly, morphological adaptation of medic to the long-term light deprivation was boosted by mycorrhiza, probably because of C demand of AMF and due to the improved nutrition of the mycorrhizal plants. On the other hand, sudden 6-day shading caused rapid decline of shoot P content of mycorrhizal plants, accompanied with the accumulation of P...
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Actuoecology of testate amoebae in fresh water and soil environment in enteraction with fungi and their analysis with new microscopic techniques
Burdíková, Zuzana ; Holcová, Katarína (advisor) ; Jansa, Jan (referee) ; Hudáčková-Hlavatá, Natália (referee)
4 Abstract The present thesis focuses on testate amoebae (TA) and their relationship to their natural environment, as well as on relevant microscopic imaging methods. The bulk of the data has been published in original scientific papers and is compiled into three separate chapters (Pt I, Pt II and Pt III), each annotated by a brief introduction. (Pt I) The methods section is devoted to specialized microscopic techniques employed to broaden the scope of the ecological analyses. In particular, precise discrimination between live and dead individuals, biomass determination inside individual tests and a multi-modal visualization of the cytoplasm and organelles enhance the data. Laser scanning confocal microscopy and two-photon microscopy are the main imaging modalities employed to study TA morphology in detail. The data have implications for taxonomy and ecophysiology, including the use of TA as bioindicators of pollution. (Pt II) An actuoecological analysis focuses on the seasonal variability of TA species composition in a freshwater ecosystem, namely the Komo any ponds in Prague, during the course of the year. The species composition variation is correlated to simultaneously recorded limnological parameters such as temperature, pH, contamination by (heavy) metals (As, Cd, Mn, Ni, Fe, Pb), polycyclic aromatic...
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Dynamics of carbon and phosphorus flows in arbuscular mycorrhizal symbiosis
Konvalinková, Tereza ; Jansa, Jan (advisor) ; Baláž, Milan (referee) ; Kolaříková, Zuzana (referee)
Dynamics of carbon and phosphorus flows in arbuscular mycorrhizal symbiosis Mgr. Tereza Konvalinková (doctoral thesis) Abstract Arbuscular mycorrhizal fungi (AMF) are widespread and highly specialized root symbionts, which gain all of their carbon (C) from the hosts, supplying plants with mineral nutrients (particularly with phosphorus, P) in return. This thesis focuses on the size and flexibility of C and P flows in arbuscular mycorrhiza in relation to environmental conditions, in particular to light and P availability. The indications that the symbiotic flows are regulated actively by both partners are discussed. The main findings are presented as a compilation of separate scientific works (two research articles, one review and one book section). A glasshouse experiment has shown that both mycorrhizal benefits and mycorrhizal colonization of medic (Medicago truncatula) by an AMF species (R. irregularis) decline along the gradient of decreasing light intensity. Interestingly, morphological adaptation of medic to the long-term light deprivation was boosted by mycorrhiza, probably because of C demand of AMF and due to the improved nutrition of the mycorrhizal plants. On the other hand, sudden 6-day shading caused rapid decline of shoot P content of mycorrhizal plants, accompanied with the accumulation of P...
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Plant sugar metabolism and arbuscular mycorrhizal symbiosis
Konečný, Jan ; Jansa, Jan (advisor) ; Gryndler, Milan (referee)
The study of arbuscular mycorrhizal symbiosis (AMS) - the mutualist relationship between the most of land plants and evolutionary old fungal group Glomeromycota - is becoming a prestigious topic. The prevalence of and extent of physiological action of AMS on plants is very interesting for the plant biology itself, but its importance grows, notably in time of global climate change, frequent soil degradation and ascending exhaustion of mineral fertilizer reserves. Although the flows in AMS of some minerals, like of phosphorus was enlightened, carbon exchange between the symbionts is still poorly understood. In this experimental work, I utilized the boom of molecular and bioinformatic methods in the quest for completely unexplained carbon flows. The organisms used include barrel medic (Medicago truncatula), the model legume for symbiotic relationships, biotic, and abiotic stresses; Rhizophagus irregularis, the widely used fungus for such experimental studies of AMS; and Sinorhizobium meliloti, the nodulating nitrogen-fixing bacterium compatible with the barrel medic. Two variants - mycorrhizal (M+) and non-mycorrhizal (NM) plants were subjected to several levels of analysis. I have checked the variants, did the measurements of phosphorus and nitrogen contents, as well as I probed the plants with...
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How works mycorrhizal pathway in phosphorus acquisition?
Konečný, Jan ; Jansa, Jan (advisor) ; Janoušková, Martina (referee)
The plant takes up mineral nutrients by its roots from the soil. Minerals are available in the soil solution in the form of ions and can be translocated across the cytoplasmatic membrane into the cell of the plant. If the plant is alone, we talk about direct pathway. In case of some minerals, which are not available so easily, the plant finds solution in mutualistic relationship - the mycorrhizal symbiosis. By mycorrhizal pathway the nutrients come from much larger volume of soil, than the plant could reach, and intake of low-mobile elements, like phosphorus, becomes facilitated. How is the phosphorus taken up through mycorrhizal pathway, how is it regulated and accessory knowledge are the topic of this bachelors thesis.
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Actuoecology of testate amoebae in fresh water and soil environment in enteraction with fungi and their analysis with new microscopic techniques
Burdíková, Zuzana ; Holcová, Katarína (advisor) ; Jansa, Jan (referee) ; Hudáčková-Hlavatá, Natália (referee)
4 Abstract The present thesis focuses on testate amoebae (TA) and their relationship to their natural environment, as well as on relevant microscopic imaging methods. The bulk of the data has been published in original scientific papers and is compiled into three separate chapters (Pt I, Pt II and Pt III), each annotated by a brief introduction. (Pt I) The methods section is devoted to specialized microscopic techniques employed to broaden the scope of the ecological analyses. In particular, precise discrimination between live and dead individuals, biomass determination inside individual tests and a multi-modal visualization of the cytoplasm and organelles enhance the data. Laser scanning confocal microscopy and two-photon microscopy are the main imaging modalities employed to study TA morphology in detail. The data have implications for taxonomy and ecophysiology, including the use of TA as bioindicators of pollution. (Pt II) An actuoecological analysis focuses on the seasonal variability of TA species composition in a freshwater ecosystem, namely the Komo any ponds in Prague, during the course of the year. The species composition variation is correlated to simultaneously recorded limnological parameters such as temperature, pH, contamination by (heavy) metals (As, Cd, Mn, Ni, Fe, Pb), polycyclic aromatic...
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