Rapid Adjustments in Thermal Tolerance and the Metabolome to Daily Environmental Changes – A Field Study on the Arctic Seed Bug Nysius groenlandicus

• Published in: Frontiers in Physiology
• Main Authors: Noer, Natasja Krog, Sørensen, Mathias Hamann, Colinet, H, Renault, D, Bahrndorff, Simon, Kristensen, Torsten Nygaard
• Other Authors: Aalborg University Denmark (AAU), Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR), 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), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), This work was supported by a grant from the Danish Council for Independent Research (DFF8021-00014B), the European co-funded Partnership BiodivClim-191 ASICS (0156-00024B), and Carlsberg (Carlsbergfondet, CF17-0415). Travel grants was provided by North2North and SAFT (Selskab for Arktisk Forskning og Teknologi). Metabolomics analyses were supported by IRP CNRS “PRICES” and IPEV 136 “Subanteco.”
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: arctic; climate change; diurnal environmental variation; GC-MS metabolomics; insects; phenotypic plasticity; temperature variation; thermal tolerance; [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology; [SDV.EE.BIO]Life Sciences [q-bio]/Ecology; environment/Bioclimatology; Arctic; Climate change; greenlandic
• Online Access: https://univ-rennes.hal.science/hal-03585727; https://univ-rennes.hal.science/hal-03585727/document; https://univ-rennes.hal.science/hal-03585727/file/pdf; https://doi.org/10.3389/fphys.2022.818485

International audience Laboratory investigations on terrestrial model-species, typically of temperate origin, have demonstrated that terrestrial ectotherms can cope with daily temperature variations through rapid hardening responses. However, few studies have investigated this ability and its physiological basis in the field. Especially in polar regions, where the temporal and spatial temperature variations can be extreme, are hardening responses expected to be important. Here, we examined diurnal adjustments in heat and cold tolerance in the Greenlandic seed bug Nysius groenlandicus by collecting individuals for thermal assessment at different time points within and across days. We found a significant correlation between observed heat or cold tolerance and the ambient microhabitat temperatures at the time of capture, indicating that N. groenlandicus continuously and within short time-windows respond physiologically to thermal changes and/or other environmental variables in their microhabitats. Secondly, we assessed underlying metabolomic fingerprints using GC-MS metabolomics in a subset of individuals collected during days with either low or high temperature variation. Concentrations of metabolites, including sugars, polyols, and free amino acids varied significantly with time of collection. For instance, we detected elevated sugar levels in animals caught at the lowest daily field temperatures. Polyol concentrations were lower in individuals collected in the morning and evening and higher at midday and afternoon, possibly reflecting changes in temperature. Additionally, changes in concentrations of metabolites associated with energetic metabolism were observed across collection times. Our findings suggest that in these extreme polar environments hardening responses are marked and likely play a crucial role for coping with microhabitat temperature variation on a daily scale, and that metabolite levels are actively altered on a daily basis.