An extraordinarily high intraspecific chemical diversity, i.e. chemodiversity, has been found in several plant species, of which some are of major ecological or economic relevance. Moreover, even within an individual plant there is substantial chemodiversity among tissues and across seasons. This chemodiversity likely has ecological effects on plant mutualists and antagonists, associated foodwebs and, ultimately, biodiversity. Surprisingly, studies on interactions between plants and their herbivores or pollinators often neglect plant chemistry as a level of diversity and phenotypic variation.
The main aim of our Research Unit is to understand the emergence and maintenance of chemodiversity in plants. We address the following central questions:
1) How does plant chemodiversity vary across levels, i.e., within individuals, among individuals within populations, and among populations?
2) What are the ecological consequences of intraspecific plant chemodiversity?
3) How is plant chemodiversity genetically determined and maintained?
To investigate these questions, we focus our research on the three study species Populus nigra, Solanum dulcamara and Tanacetum vulgare. In addition, we combine field and laboratory studies with metabolomics, transcriptomics, genetic tools, statistical data analysis and modelling to understand causes and consequences of plant chemodiversity and elucidate the impacts thereof on the interactions of plants with their biotic environment. Furthermore, we want to identify general principles, which hold across different species, and develop meaningful measures to describe the fascinating diversity of defence chemicals in plants.