News
22.08.2022
Microbes protect a leaf beetle – but for a price
Researchers from Tübingen and Panama discover a novel mutualism between fungi and insects
Insects are known to rely on microbial protection during immobile developmental stages, such as eggs. But despite the susceptibility of pupae to antagonistic challenges, the role of microbes in ensuring defense during an insect’s metamorphosis remained an open question. Scientists from the Max Planck Institute for Biology in Tübingen, the University of Tübingen and the Smithsonian Tropical Research Institute, Panama, have now discovered a novel defensive partnership between a fungus and a leaf beetle. The microbe provides a protective layer around the beetle´s pupae and thus prevents predation. In exchange, the beetle disperses the fungus to its host plant, expanding its range. Now published in Current Biology, the researchers present the results of their study.
Antagonistic interactions are widespread in nature, spurring the evolution of protective traits. In insects, as with other animals, symbioses with beneficial microbes can serve as a source of defensive adaptations.
An impactful mutualistic relationship
In their study, the biologists discovered a mutualistic partnership between the ascomycete Fusarium oxysporum and Chelymorpha alternans, a leaf beetle: The fungus protects the pupae of the leaf beetle against predators. And in exchange, the beetle disperses the fungus to its host plants and thus contributes to its transmission.
“The fungus retained a metabolic profile that reflects its dual lifestyle,” explains Hassan Salem, Research Group Leader at the Max Planck Institute for Biology and senior author of the study. “Our findings show a mutualism ensuring pupal protection for an herbivorous beetle on the one hand, in exchange for symbiont dissemination and propagation on the other hand,” Salem adds.
Contact:
Dr. Hassan Salem
Max Planck Institute for Biology Tübingen
Max Planck Research Group Leader
Mutualisms Research Group
Phone: +49 7071 601-1367
hassan.salem@tuebingen.mpg.de
Dr. Aileen Berasategui-Lopez
University of Tübingen
Department of Microbiology and Biotechnology
Cluster of Excellence “Controlling Microbes to Fight Infections” (CMFI)
CMFI Early Career Researcher
Phone: +49 7071 29-74639
aileen.berasategui-lopez@uni-tuebingen.de