Research Group Sequestration and Detoxification in Insects

Plants produce an astonishing diversity of so-called specialized metabolites to defend themselves against enemies.  Insects, however,  were able to adapt to these chemical defense compounds, for example by developing insensitive target sites or by enzymatic detoxification. Numerous insect species even sequester defense metabolites from their host plants and use them for their own defense against natural enemies. The central hypothesis of our research is that insect adaptations to plant chemical defenses represent evolutionary key innovations that have promoted species diversification of plant-feeding insects. To address this hypothesis, we elucidate the adaptive mechanisms enabling herbivores to overcome plant chemical defenses, and aim to identify the genetic basis and evolutionary origin of these adaptations. Specifically, we focus on the adaptations of Phyllotreta and Psylliodes flea beetles to the glucosinolate-myrosinase defense system present in their crucifer host plants. In damaged tissue, glucosinolates are enzymatically degraded to highly reactive isothiocyanates which negatively affect the performance of non-adapted herbivores. We previously showed that Phyllotreta beetles not only accumulate large amounts of intact glucosinolates in their bodies, but also evolved a beetle myrosinase which allows them to activate sequestered glucosinolates for their own purpose. In crucifer-feeding Psylliodes, the metabolism of glucosinolates appears to be much more complex. We currently investigate the mechanisms underlying sequestration and metabolism of glucosinolates in Phyllotreta and Psylliodes  and reconstruct the phylogeny of Psylliodes species in order to trace the evolution of host plant associations in this genus.

Psylliodes chrysocephala © Anna Schroll

Group Leader:

Dr. Franziska Beran
+49 (0)3641 57 1553