Nitrogen uptake, nitrogen use efficiency and regulation of ammonium transport:
Excess nitrogen from intensive agriculture pollutes the environment and groundwater. We are researching how nitrogen from model plants (Arabidopsis) and crops (wheat, maize, bean, pea, Medicago) can be used more efficiently to have less harmful effects on the environment. Besides nitrate, ammonium is a preferred source of nitrogen for plants. We are investigating how ammonium uptake is genetically and physiologically regulated, how this regulation integrates into the nitrogen and nitrate network and to what extent management and genetics can be improved to have less negative impact on the environment.
Phosphorus (P) in the form of phosphate is another important macronutrient for plants. Global P stocks are limited and P in the soil is often only available to plant roots to a very small extent. We are investigating genetic components of P efficiency traits in white lupin (with cluster roots) and in modern and old genotypes as well as in landraces of maize. New genetic components have been uncovered, but also management options using biofertilisers (microbial and non-microbial) without intrinsic nutritional value have been investigated. Of particular relevance here is the rhizosphere, the soil around the roots, which is crucially influenced by plant exudates. Its microbial communities of bacteria and fungi are also crucial for plant health.
Micronutrients in seeds and grains:
Micronutrient deficiencies are widespread in the world population and especially in poor countries with predominantly vegetarian diets. Using the model plant Arabidopsis and in beans, we increase micronutrients (Fe, Zn) in edible plant parts using physiological and genetic methods.
Interactions of nutrients and fertilisers with plant health and diseases:
Public demand for reduced use of pesticides in agriculture puts pressure on farmers to suppress diseases. Certain fertilisers and forms of fertiliser (e.g. nitrogen in its various forms ammonium or nitrate) have positive effects on plant health and can effectively suppress certain diseases. Plants use exudates to control physiology in the rhizosphere, resulting in beneficial or harmful bacterial and fungal communities.
