How do trees feed? New excellence project

Nitrogen is a central building block in the nutrition of trees (and other plants). The element is required for the formation of chlorophyll and thus for photosynthesis, but also for plant growth. Previously known mechanisms for trees to absorb nitrogen include the direct uptake of inorganic nitrogen and smaller molecules (amino acids, peptides) from soil reserves as well as indirect uptake via microbes. The excretion of proteases, i.e. enzymes that break down organic complexes (e.g. from litter), has already been confirmed for some non-woody plant species, but not yet for trees.

"This mechanism represents a competitive advantage," explains Prof. Dr. Judy Simon, head of the Department of Ecological Plant Nutrition and the new Excellence Project. "If trees use it, they don't have to 'wait' for organic matter to be broken down and mineralized by microorganisms. Nitrogen can thus be absorbed directly from the organic soil matter." The new research project aims to clarify whether this is the case and, if so, how exactly the mechanism works. As the state of Hesse announced today (6 December), it is funding the project with around 240,000 euros as part of the State Offensive for the Development of Scientific and Economic Excellence (LOEWE) - Exploration program line.

"With its focus on long-lived woody plants, this project can provide important new insights into the functioning of economically and ecologically valuable tree species and forest ecosystems," says Judy Simon. "This has great potential for forest management strategies with regard to climate change." However, a deeper understanding of nutritional competition in the soil is also important for agroforestry. Agroforestry refers to farming next to or under trees - a method that is said to have great potential in climate change.

Fighting pests with yeast cells

Another project led by Hochschule Geisenheim University is researching so-called predator yeasts, which can penetrate the cells of harmful organisms and kill them. To do this, however, they need a starvation signal, which is to be generated by molecular genetics in the project. The aim is to be able to use starving predator yeasts more effectively for the biocontrol of pathogens and thus to develop an alternative for pest control. Dr. Roland Klassen from the Department of Microbiology at the University of Kassel is involved in the project.

The LOEWE Exploration funding line is intended to give researchers the freedom to pursue novel, highly innovative research ideas.