Eine Kultivierungsmethode zur Untersuchung von Phytohormoneffekten auf Rhizosphärenprozesse

Higher plants affect processes in the rhizosphere by root exudation. The exuded compounds may directly influence nutrient availability or may serve as a substrate for various nutrient-solubilizing soil microorganisms. Furthermore, plant growth promoting effects of rhizosphere microbes include the production of a vast range of metabolites (biological active substances) that may affect plant growth directly after being taken up by the plant, or indirectly by modifying the soil environment. Phytohormones like auxines (indole-3-acetic acid, IAA), gibberellins (gibberellic acid, Ga3) or cytokinins (trans-zeatin, t-Z) belong to this groups of substances. It is well documented that cultures of several plant growth promoting microorganisms produce these phytohormones in considerable amounts. But there are only few data available about long-term effect of these coumpounds on rhizosphere processes of intact plants.