Adverse environmental effects have a significant impact on plants' life and influ-ence the plants' metabolome. Specific stress-related responses are manifested both on plant development and its metabolites. This thesis entitled "Plant metabolome and its response to stress" outlines the composition of plant metabolome and reviews stress-related metabolites and metabolomics processes. The experimental part summarizes the results of two independent experiments. First, Hordeum vulgare response to stress was followed via targeted LC-MS metabolomics and proteome analysis. Next, a drought response was analyzed in Solanum lycopersicum via GC-MS metabolome profiling. Results highlighted a tissue-specific response to stress and pinpointed several putative abiotic stress markers