Symbiont-mediated detoxification in pine weevils

In addition to the diversity of nutritional benefits that bacterial symbionts can confer to their insect hosts, they have also been hypothesized to contribute to the detoxification of noxious plant secondary metabolites, but empirical evidence is so far lacking. We are trying to fill this gap by studying the pine weevil (Hylobius abietis) and the potential involvement of its associated microbiota in terpene degradation. The pine weevil is a pest for European conifer forests, where it feeds on the bark and phloem of pine and spruce. It spends its whole life in close contact to terpenes (the conifer’s main chemical defense). Other insects are known to be highly susceptible to these compounds, which have often been found to act as antifeedants and deterrents and can cause neural damage and disruption of the gut membrane. However, they have little or no negative effect on the pine weevil. We are studying how Hylobius abietis copes with terpenes in its diet and whether its gut microbiota is involved in the detoxification of these compounds. To this aim, we are using culture-dependent and molecular methods to characterize the microorganisms present in the weevil’s gut, as well as metabolic and genomic analyses to assess their function. This study can shed some light on how insects deal with plant chemical defenses and how symbioses could help insects to colonize new ecological niches.

Researchers:
Aileen Berasategui (MPICE), Martin Kaltenpoth, in Kooperation mit Jonathan Gershenzon und Axel Schmidt (MPICE)

Selected publications:

Berasategui, A., Salem, H., Paetz, C., Santoro, M., Gershenzon, J., Kaltenpoth, M., Schmidt, A. (2017), Gut microbiota of the pine weevil degrades conifer diterpenes and increases insect fitness. Molecular Ecology 26 (15): 4099-4110.

Berasategui, A., Axelsson, K., Nordlander, G., Schmidt, A., Borg-Karlson, A.-K., Gershenzon, J. Terenius, O., & Kaltenpoth, M. (2016) The gut microbiota of the pine weevil (Hylobius abietis, Coleoptera: Curculionidae) is similar across Europe and resembles that of other conifer-feeding beetles. Molecular Ecology 16: 4014-4031.