Paul David Grünhofer's Master thesis was awarded with the Prize for the Best Plant Science Master Thesis, which was carried out at Rheinische Friedrich-Wilhelms-Universität Bonn in the year 2019.
Formation and chemical composition of suberin in poplar roots
Grünhofer analysed spatiotemporal suberin deposition in poplar roots and its chemical composition. Most parts of the results comprise control as well as osmotic stress conditions.
Plants employ suberization of root tissue as mechanism of protection against various biotic and abiotic environmental stresses. The tissue-specific formation of suberin under control and stress conditions has been investigated by use of in-vitro tissue culture, hydroponics, fluorescence microscopy and gas chromatography. The main focus of this thesis was to establish a scientifically standardized and reproducible method to grow and treat poplar roots with a variety of different stresses, in order to lay a solid foundation for future research. In addition to that it could already be shown by use of fluorescence microscopy that a treatment of the roots with a mild osmotic stress ( 0.4 MPa) resulted in a shift of the onset of suberization towards the root tip, if compared to control conditions. An analytical preparation and examination of the harvested roots by gas chromatography showed a remarkable overlap of the suberin composition to that of the commonly used model organism Arabidopsis thaliana. A quantitative evaluation to answer the question if the mild osmotic stress in fact does induce an increased suberization of the root tissue could not be answered within this work due to limited time. However, answering this question as well as the examination of more severe osmotic stresses (-0.6 MPa and -0.8 MPa) and the treatment of roots with salt stress will follow in the seamlessly started dissertation. These topics are especially interesting due to rising temperatures in the future, which will make water (represented by osmotic stress) and thereby caused salt stress an even more prominent problem in our soils
Paul David Grünhofer conducted this thesis at the Institute for Cellular and Molecular Botany (IZMB) in the group of Prof. Dr. Lukas Schreiber.