Master Thesis in the Department of Entomology

Topic: Interaction of beetle polygalacturonases with putative plant inhibitory proteins

The herbivorous mustard leaf beetle Phaedon cochleariae feeds on a variety of plants and possesses different digestive enzymes targeting plant cell wall polysaccharides. Amongst those, polygalacturonases (PGs) hydrolyse the cell wall polysaccharide pectin (Kirsch et al. 20141). Plant-derived, cell wall-associated polygalacturonase-inhibiting proteins (PGIPs) counteract microbial PGs and thus contribute to the plant´s defence against phytopathogens. However, direct interactions between beetle PGs and plant inhibitory proteins have not yet been investigated.

We identified putative PGIPs from the beetles’ food plant Chinese cabbage (Brassica rapa ssp. pekinensis) and, subsequently, would like to study the effect of these candidate proteins on P. cochleariae.

In this thesis, the model plant Arabidopsis thaliana will be genetically modified to express putative PGIPs. In addition to the plant’s response to beetle feeding (gene expression analysis by qPCR), the performance of beetles feeding on plants expressing these potential defensive proteins will be studied in vivo.

We are looking for a student from the natural science field who is highly motivated for an interdisciplinary topic combining molecular biology with ecological in vivo studies. The thesis can be either in German or (preferably) in English.

If you are interested or have further questions, please feel free to contact:
Wiebke Häger, Max Planck Institute for Chemical Ecology, Jena


1DOI: 10.1016/j.ibmb.2014.06.008



A) Young, transgenic A. thaliana in a Petri dish, B) A. thaliana and P. cochleariae larvae and adults