By growing in a soil plants change the biotic and abiotic properties of the soil in which they grow. This can influence the performance of plants that grow in the same soil subsequently and is... Show moreBy growing in a soil plants change the biotic and abiotic properties of the soil in which they grow. This can influence the performance of plants that grow in the same soil subsequently and is known as plant soil feedback (PSF). Species largely differ in how they influence the soil while they grow in it and how they react to conditioned soil. So far PSF was mainly shown to influence biomass of plants and certain specific chemical compounds in plants. This thesis demonstrates how the whole metabolome of a range of different plants changes due to different microbiomes in the soil and that the influence of soil on the metabolome of plants can be stronger than the effect of herbivory. Furthermore, this thesis shows how these PSF change over time and on different spatial scales and which methods are most suitable to study the metabolomic response of plants. Show less
Plant exudates appeared long time ago in the history line of life in the early Devonian. They are typical saps produced by specialized cells. They can be naturally excreted outside or right after... Show morePlant exudates appeared long time ago in the history line of life in the early Devonian. They are typical saps produced by specialized cells. They can be naturally excreted outside or right after plants are damaged or infected. Through time, diverse cultures recognized them as valuable sources of natural medicines. Of various types of plant exudates, the most outstanding are gums, mucilage, essential oils, oleoresins, resins, phloem like saps, and latexes. Regardless of their commercial importance, in the aspect of biology, plant exudates are believed to be involved in plant defense mechanisms, but their roles still remain unclear. In this thesis, based on diverse experiments, many features of plant exudates were unveiled. Interestingly, even if plant exudates possess a broad chemical diversity, their specialized biological functions resulted in less variation of their metabolomes as compared with their bearing tissues. This lower variation indicates that plant exudates might partake of a general-broad defense against herbivores and pathogens in their bearing tissues. This defense involves both mechanical and chemical traits which might complement and modulate each other, eventually resulting in a chemo-mechanical defense layer. Of the diverse chemicals in plant exudates, terpenes are one of the most common metabolites in these saps. Show less
