Plants are fascinating biological systems with a great potential for adaption of their developmental programs to environmental cues. In contrast to animals, plants cannot run away and thus they had to develop specialized mechanisms to react to rapid changes in the environment. These plant-specific mechanisms including light perception, tropism and developmental reprogramming (de novo organ formation, tissue re-shaping), represent highly dynamic regulatory processes that are linked and intertwined on the molecular, cellular and tissue levels. The ultimate communication between these different levels is the key to understand how plants realize their developmental decisions. Cell signaling, tissue polarization, directional transport of signaling molecules within tissues are among those biological processes that allow for such multilevel organization in plant development. Nevertheless our understanding of these processes remains largely elusive.
This doctoral thesis demonstrates the results of multidisciplinary studies at the interface between several scientific disciplines, including mathematics, computer science (under supervision of Prof. Willy Govaerts) and cell and developmental biology (under guidance of Prof. Jiří Friml). Therefore, I will utilize state-of-the-art mathematical and computational techniques combined with the most recent biological data to address cell and tissue polarities as well as graded distribution patterns of the plant phytohormone auxin, in the context of plant developmental flexibility. The main goal of the research presented herein was to explore general principles of auxin feedback regulation and its outstanding roles in auxin-driven plant development.
A special focus was given to the combination of local auxin signaling cues (inside and outside of the cell), subcellular dynamics (trafficking of auxin carriers) and cell-type specific factors (spatial patterns of gene activity) to account for the developmental patterns observed in planta such as canalization of auxin transport, leaf venation patterning, tissue regeneration and establishment and maintenance of cell and tissue polarities. The core of the thesis will start with a general introduction to the models for auxin-mediated plant development and will be followed by presentation of various scientific results and their potential implications for hopefully better understanding of patterning mechanisms in plants. Finally, the summarizing chapter of this thesis aims to translate the results of these various studies to the more general concept of the local auxin feedback regulation in plants
