In recent years, there has been an increasing interest in utilizing nuclear magnetic resonance (NMR) spectroscopy metabolomics to understand different biochemical mechanisms of living organisms. Metabolomic profiling can provide a comprehensive snapshot from multiple biological mechanisms in the studied subject as NMR allows simultaneous detection of a wide range of metabolites. The main aim of this thesis was to analyze, qualify and quantify the metabolites in a model plant, Arabidopsis thaliana (Arabidopsis), and two different mushroom families Hypholoma and Kuehneromyces under different circumstances. Metabolomic investigations of Arabidopsis included metabolic studies of distinct genotypes of Arabidopsis in different developmental stages and determination of the impact of light intensity on metabolomic adjustments in Arabidopsis. The studies revealed the essential role of these conditions on elevated levels of several metabolites. However, no metabolomics changes between different genotypes of Arabidopsis could be seen with NMR. The study regarding mushrooms demonstrated influences of the drying method on alteration of metabolites in fresh and herbarium mushroom families Hypholoma and Kuehneromyces. It was discovered that air-dried herbarium samples from different ages (up to 25 years) are stable and can be utilized for different purposes in the future. 1H NMR (proton NMR) was applied to distinguish and characterize metabolic profiles and key components of the study subjects under diverse conditions. In order to analyze the data, different multivariate methods were performed.

The new understanding arising from NMR metabolomic screening of Arabidopsis plants and mushrooms addressed in this thesis can be applied in future studies in plant genetics, investigation of different biochemical mechanisms in plant stress resistance and development as well as in further NMR based investigations of the metabolites in various taxa of mushrooms.