Plants communicate via chemistry. They produce natural substances such as toxic and bitter alkaloids to defend themselves against pests. Likewise, plants produce scents. They use these to attract bees and other pollinators or predatory insects that rid plants of voracious caterpillars. Unlike synthetic pesticides, natural compounds have little or no negative impact on overall biodiversity. If we better understand this natural "self-defense" of plants, we can produce our vegetables more sustainably.

Technically, yes, but research by colleagues on how corn roots communicate with beetle larval enemies has shown that certain corn varieties no longer produce the scents that attract these underground enemies. In current breeding, these traits were neglected because we had synthetic pesticides. We now need to re-incorporate the ability of plants to defend themselves chemically into new breeding programs. To do this, we must first understand which chemicals are important and which genes in plants are responsible for them.

When it is too hot or too dry, plants have to adapt in order to survive. This consumes energy and resources, for example nitrogen. Plants may then no longer have the strength to defend themselves against pests. However, it is also possible that adaptations to drought stress make the plant more resilient. Such adaptations are evident, for example, in plants developing smaller but thicker leaves to reduce evaporation of water through the leaves. Since pests and heat stress occur simultaneously under current climate conditions, we at the IGZ are also researching such issues in a direct context.

Plants have survived millions of years on our planet, much longer than we humans have. There have been times when our planet may have been much warmer, and there have also been larger predators like the dinosaurs. Plants survived all of this with the help of the chemistry of their natural products and their adaptability. As a chemical ecologist, I try to understand how they did that. With this knowledge, we can ensure that we can continue to produce vegetables and other plant foods safely and sustainably in sufficient quantities to reliably supply the world's population with high-quality, healthy food.

My research focuses on the chemical and molecular ecology of plant-insect interactions. That involves how plants optimize their response to simultaneous attacks, especially between above-ground and below-ground herbivores. We also explore whether certain fungi and mycorrhizae stimulate plants to defend themselves better. I also seek to understand how plants have come to produce thousands of natural products over the course of evolution. We investigate the ecological role of this chemical diversity in plants - in other words, which plant natural substance has which effect. With this, my research provides basic knowledge that is incorporated into breeding programs for plants so that they can better defend themselves. Together with breeding companies, we translate this knowledge into practice.

Interview: Beatrix Boldt