Overcoming deterrent metabolites by gaining essential nutrients: A lichen/snail case study

Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Alice Gadea, Maryvonne Charrier, Mathieu Fanuel, Philippe Clerc, Corentin Daugan, Aurélie Sauvager, Hélène Rogniaux, Joël Boustie, Anne-Cécile Le Lamer, Françoise Lohézic - Le DevehatAbstractSpecialised metabolites in lichens are generally considered repellent compounds by consumers. Nevertheless, if the only food available is lichens rich in specialised metabolites, lichenophages must implement strategies to overcome the toxicity of these metabolites. Thus, the balance between phagostimulant nutrients and deterrent metabolites could play a key role in feeding preferences. To further understand lichen-gastropod interactions, we studied the feeding behaviour and consumption in Notodiscus hookeri, the land snail native to sub-Antarctic islands. The lichen Usnea taylorii was used because of its simple chemistry, its richness in usnic acid (specialised metabolite) and arabitol (primary metabolite) and its presence in snail habitats. Choice tests in arenas with intact lichens versus acetone-rinsed lichens were carried out to study the influence of specialised metabolites on snail behaviour and feeding preference. Simultaneously, usnic acid and arabitol were quantified and located within the lichen thallus using HPLC-DAD-MS and in situ imaging by mass spectrometry to assess whether their spatial distribution explained preferential snail grazing. No-choice feeding experiments, with the pure metabolites ...
Source: Phytochemistry - Category: Chemistry Source Type: research