Supervisor: Stefanie Wienkoop
PhD student: Julian Preiner
Group: Division of Molecular Systems Biology, Department of Ecogenomics and Systems Biology
Tungsten (W) and molybdenum (Mo) are economically important transition elements residing in the chromium group of the periodic table. Due to a myriad of industrial applications, ranging from household appliances to war-ammunition and high-tech products, they are increasingly discharged into the environment. However, little is known about their eco-toxicology. While molybdenum is an important micronutrient and serves as co-factor in various key enzymes of microbes, plants and other higher lifeforms, tungstoenzymes are only found in some archaea and bacteria. Due to their chemical similarities regarding structure, atomic radii and electron configuration, it is proposed that molybdenum ions bound to co-factors of enzymes can be substituted by tungsten. In plants it has been repeatedly demonstrated that tungsten renders the four molybdoenzymes (nitrate reductase, aldehyde oxidase, xanthine dehydrogenase and sulfite oxidase), functionless if incorporated instead of its “twin element”. In addition, the rhizobial molybdoenzyme, nitrogenase, was found to retain its function even if tungsten is incorporated into the enzyme.
Although it has been shown that both transition metals can be phytotoxic when occurring in excess concentrations, knowledge about their effect on plant metabolic processes is still limited. Due to preliminary experimental data obtained for W, we believe that the two transition metals interfere with integral metabolic pathways, especially phosphorous and nitrogen dependent processes. We aim to comprehensively understand the molecular mechanisms behind phyto-toxicity and stress response induced by excess tungsten and molybdenum as well as stress alleviation through Rhizobium symbiosis.
In order to uncover the mechanisms that govern toxicity of Mo and W in plants as well as the microsymbiont effect, a multilevel assessment (proteomic, metabolomic, enzymatic, physiologic and microscopic) of N-metabolism, antioxidative system, nutritional status is performed.
Please find a list of publications here.