Exploring and Exploiting Plant Defense

In our research group, we study how plants adapt to environmental stresses, particularly to herbivory. We combine high-throughput sequencing approaches with experimental evolution, metabolic profiling, and genetic manipulation to elucidate the genetic, epigenetic, and physiological bases of plant adaptation using duckweeds as a model system. Furthermore, we use the acquired methods to transform duckweeds into a green biofactories to produce high-value metabolites in plants. Through these studies, we will improve our conceptual understanding of plant defense and explore potential industrial applications.



Activation of specialized metabolites by herbivorous insects

(c) Laura Böttner

Toxic secondary metabolites are of central importance to protect plants against herbivores. Many toxins are stored as precursors, so called protoxins, and are activated by compartmentalized enzymes upon tissue disruption. Curiously, protoxins are not always activated by plant-derived enzymes: in many cases, they seem to be cleaved by digestive enzymes from the herbivores. To date, the genetic basis of this phenomenon as well as its ecological implications are not well understood. To shed light into these aspects, we are studying the metabolization of taraxinic acid β-D-glucopyranosyl ester (TA-G), a sesquiterpene of the common dandelion (Taraxacum officinale) that repels its major root herbivore, the common cockchafer larva (Melolontha melolontha). Using a combination of heterologous expression and RNA interference, we aim to identify the genetic basis of TA-G deglycosylation during M. melolontha feeding, which will allow us to elucidate the ecological consequences of this phenomenon. This project will thereby assess the importance of the insect digestive system in mediating plant-herbivore interactions.



The role of DNA methylation in transgenerational plasticity

DNA methylation is hypothesized to mediate transgenerational plasticity across asexual plant generations. Yet, experimental evidence for this hypothesis is scarce. Using the giant duckweed, one of the world´s fastest reproducing flowering plants, we study how variation in DNA methylation is generated, whether such variation is transmitted across asexual generations, and whether inherited methylome variations alter plant phenotype and stress resistance. Together, these studies will provide evidence whether asexually reproducing plants may resist and adapt to environmental stresses through epigenetic mechanisms.




Transforming duckweeds into green biofactories

Duckweeds are rapidly growing, easy to cultivate and edible for both livestock and humans. As such, duckweeds are promising green biofactories to produce economically valuable metabolites. To enhance these applications, we are optimizing tools for genetically manipulating both the nuclear and the plastid genomes of duckweeds. These studies will lay the foundation for transforming duckweeds into efficient green biofactories to produce economically valuable metabolites in an environmentally friendly way.