Sectorial land snail damage to the lichen Argopsis friesiana could be explained by metabolite profiles

• Published in: Planta Medica
• Main Authors: Gadea, Alice, Lohézic-Le Dévéhat, Françoise, Le Lamer, Anne-Cécile, Le Pogam, P., Ertz, Damien, Charrier, Maryvonne, Boustie, Joël
• Other Authors: Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS), Ecosystèmes, biodiversité, évolution Rennes (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Meise Botanic Garden Belgium (Plantentuin)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: Sub-antarctic lichens; metabolites profiling; DART-MS; Notodiscus hookeri; chemical ecology; [CHIM]Chemical Sciences; Antarctic; Possession Island; Antarc*
• Online Access: https://univ-rennes.hal.science/hal-01446729; https://doi.org/10.1055/s-0036-1596670

International audience Notodiscus hookeri is the only native land snail of the sub-Antarctic present in Crozet Archipelago. Two shell ecophenotypes co-exist on Possession Island and feed exclusively on lichens [1] that are symbiotic organisms widely distributed in sub-Antarctic islands. To improve our understanding of lichen-snail trophic interactions, the endemic tripartite lichen Argopsis friesiana was selected. The snail belonging to the organic ecophenotype occurs sympatrically with A. friesiana. Profiling and quantification of the major secondary metabolites in the whole lichen were carried out by LC-DAD-MS. Two main compounds were identified, the depside atranorin (8.2 mg g-1 DM) and the depsidone argopsin. Besides, a screening of primary metabolites was carried out to determine which compounds could be useful for the snail energetic demands. Glutamate, glutamine, gamma-aminobutyric acid and alpha-alanine were the main amino acids found in the lichen in low concentrations (0.4 mg·g-1 DM). Carbohydrates, including arabitol (10.2 mg g-1), mannitol (4.0.10-4 mg g-1) and sucrose (3.0.10-4 mg g-1), were also identified. In cultivation, N. hookeri snails were fed with fructified thalli of A. friesiana. Snails (n = 20) ate the podetia cortex and phyllocladia but they clearly avoided apothecia, the reproductive organs. This sectorial damage of the lichen by the snail suggested a differential distribution of the metabolites. Therefore, a profiling of secondary compounds was performed by Direct Analysis in Real Time – Mass Spectroscopy (DART-MS) [2] on each morphological part of the lichen (phyllocladia, apothecia, podetia and cephalodia). The identification and distribution of secondary metabolites, fatty acids, amino acids and carbohydrates should help us to determine whether metabolites affect snail feeding choice and which of them could be involved.