Fiziološke raziskave mikorize (Slovene)

Mycorrhiza, a symbiotic association between fungi and roots of higher plants, is a significant factor in many ecosystems due to its physiological function and ubiquity. In this project the regulatory role of plant hormones, especially jasmonic acid (JA), in the development of ectomycorrhiza and arbuscular mycorrhiza was studied. In vitro experiments revealed differences in the response of mycorrhizal and parasitic fungi to exogenously applied JA, as shown by the mineral content, membrane fluidity and growth studies. Research on the fungus Pisolithus tinctorius gave interesting insights into JA metabolism. A regulatory role of JA in mycorrhizae development was confirmed in experiments with spruce seedlings where JA in optimal concentrations stimulated infection. Changes in seedling protein patterns were also established. Research on the role of cytokinins in mycorrhization confirmed the importance of these growth regulators in determining the species and ecotypic specificity of mycorrhizae. Interactions of mycorrhizal fungi, in particular ectomycorrhizal fungi, with heavy metals are another field of our research. Tolerance of fungi and response of inoculated mycorrhizal plants to Pb was the main focus. The possible role of cytokinins in Pb toxicity was also examined. Exogenously applied cytokinin decreased the Pb uptake in spruce seedling and influenced its distribution. Therefore, rhizosphere cytokinins, as from the mycelium of a mycorrhizal fungus, could significantly influence Pb transport, and consequently its toxicity in plants.