Research
Group of auxin transport (Head: Eva Zažímalová)
We focus on the
molecular mechanism of polar auxin transport and on the ways of its
regulation.
Plant hormone auxin is a key regulator of many developmental processes in plants. It plays a major role in control of temporal and spatial aspects of plant growth and, as such, it co-ordinates plant development. In contrast to other plant growth regulators (plant hormones), in some tissues auxin molecules are transported to long distances through plant body and their transport is directional (polar).
Mechanism of the polar auxin transport is based on physical-chemical properties of auxin molecules and on their molecular forms inside and outside cells. It is a very complex and dynamic process with many levels of regulation. More…
Group of metabolism and physiological function of cytokinins (Head: Václav Motyka)
We are engaged in the research of cytokinins, i.e. plant hormones
that regulate cell division and differentiation and thus efficiently control
plant growth and development.
Cytokinins are naturally occurring phytohormones that act in concert with auxins to regulate cell division and differentiation and thus efficiently control plant growth and development. Transient enhancement of auxin in relation to cytokinin levels induces root formation while the opposite shift results in shoot formation. Re-establishment of the two hormone quantitative ratios (hormonal homeostasis) is essential for further development of induced events.
Endogenous levels of bioactive cytokinins and their mode of action in plants are regulated at different levels and by various mechanisms concerning biosynthesis, metabolic conversions, inactivation and degradation as well as signalling pathways and transport. More…
Group of the role of phytohormones in the interaction with environment (Head: Radka Vaňková)
We focus on the elucidation of plant defence
mechanisms, with the aim to contribute to the development of effective
strategies to enhance stress tolerance of plants.
Plants have evolved complex systems of defence against, and adaption to, the variable and often potentially damaging environmental conditions to which they are exposed during their growth and development. Due to their sessile character, plants need to respond very dynamically to various abiotic (drought, extreme temperatures, high light intensity) as well as biotic stresses (pest and pathogen attacks).
Drought belongs to the most frequent abiotic stresses. Plants cope with water stress by preferential protection of upper leaves and apex. Gradual degradation of macromolecules takes place in lower leaves, nutrients being transported to upper leaves. Plant hormones cytokinins increase the sink strength.
We found that stress induced polarization of tobacco plants has been mediated by the establishment of cytokinin gradient in favour of upper leaves. This gradient is during severe water deficit strengthened by the stimulation of cytokinin degradation by cytokinin oxidase/dehydrogenase (CKX) in lower leaves. More…
Group of mathematical modelling (Head: Klára Hoyerová)
Our laboratory uses mathematical modelling approach
to unravel regulatory mechanisms of polar auxin flow in plants.
Nowadays, mathematical modelling is used as a tool for studying auxin transport more and more often. Present models are sometimes excessively simplified and/or do not reflect the structure of the real system properly. We have focused on construction of a detailed model of auxin transport mechanisms in plant cells using experimental data to analyse particular transport mechanism separately (an analytical-synthetic approach). These data include measurements of accumulation kinetics of radiolabeled auxins in cell suspensions and HPLC analysis of radiolabeled auxin metabolism, which has both provided valuable information about auxin transport properties at cellular level. More…
Analytical unit (Head: Petr Dobrev)
The analytical unit of
our laboratory works on improving of existing and developing of new analytical
procedures for purification, quantitation and metabolic profiling of
plant hormones and some other bioactive substances of plant origin. More…