This news release is available in German.
Scientists at the Max Planck Institute for Chemical Ecology in Jena, Germany, have discovered the decisive biological stimulator for the accumulation of defensive substances in leaf beetle larvae used by the insects to fend off predators: ABC transport proteins, which are found in large quantities in glandular cells of the larvae. The poplar leaf beetle Chrysomela populi is able to transport salicin, which is found in its leafy diet and is absorbed in its midgut, via several cell membranes into its defensive glands, where the substance is converted into the defensive compound salicyl aldehyde. The research results not only shed light on the molecular evolution of the defensive system in leaf beetle larvae but also help to elucidate cell biological processes of sequestration in animal tissues. (eLIFE, December 3, 2013, DOI: 10.7554/eLife.01096)
Food chains and how to escape them
Leaf beetle larvae are part of food chains. They are attacked by predatory insects and parasites, such as hover flies and bugs. To protect themselves, some leaf beetle larvae have developed sophisticated mechanisms. Upon being disturbed, they emit a deterrent from their defensive glands as little droplets on their back. The defensive substances in the secretion are synthesized by the larvae from chemical precursors ingested when the larvae feed on leaves; instead of synthesizing these substances on their own, they save energy. In the case of the poplar leaf beetle, the chemical precursor is salicin, which is present in the leaf tissues of poplars and willows. A sophisticated transport network carries the precursors from the gut into the defensive glands. Only two more enzymatic steps are necessary in order to accumulate the d
|Contact: Dr. Antje Burse|
Max Planck Institute for Chemical Ecology