Genome-scale modelling, prediction and experimental testing of cross-feeding interactions within the root microbiota of Arabidopsis thaliana Observatoire des Sciences de l’Univers de Rennes (OSUR),Université de Rennes 1,Salle de conférence, 8 décembre 2021, Rennes.

Genome-scale modelling, prediction and experimental testing of cross-feeding interactions within the root microbiota of Arabidopsis thaliana
Observatoire des Sciences de l’Univers de Rennes (OSUR), Université de Rennes 1, Salle de conférence, le mercredi 8 décembre à 09:00
Jury : François Buscot (Professeur, Helmhotz centre for environmental research – Rapporteur) Jérémie Bourdon (Professeur, Laboratoire des sciences du numérique de Nantes – Rapporteur) Anne Siegel (Directeur de recherche, IRISA/INRIA Rennes, Examinatrice) Christophe Mougel (Directeur de recherche, UMR IGEPP, INRAE, Examinateur) Philippe Vandenkoornhuyse (Professeur, Université de Rennes 1; directeur de thèse) Stéphane Hacquard (Group leader, Max planck Institute for Plant Breeding Research ; co-directeur de thèse) Titre complet : Genome-scale modelling, prediction, and experimental testing of cross-feeding interactions within the root microbiota of Arabidopsis thaliana: a microbial system ecology framework Résumé/Abstract: Microbial communities form complex, intricate networks of interacting organisms that highly participate in their structure and dynamics. Among these interactions, the exchange of metabolites between organisms, i.e. cross-feeding, is more and more considered as highly frequent and important. Cross-feeding behaviors can be investigated in silico with reconstructed metabolic networks, that allow modelling of organisms’ metabolism, hence predictions of possibly exhcnaged metabolites. These modelling approaches take place in a particular framework, microbial system ecology, which organizes numerous modelling approaches and their experimental validation, from bottom-up to top⁻down scales. In this work, we used such a framework on a representative part of the root microbiota of Arabidopsis thaliana to carry out numerous and putative combinations of bacterial strains that would allow the production of metabolites that were not producible by single strains. We also modelled the impact of available nutrients on strains metabolism, and predicted that cross-feeding can largely compensate severe nutritional constraints. In parallel, we used simple metrics correlating the capacity to exchange metabolites with bacteria’s metabolism and phylogenetic distance. Such metrics were tested experimentally, with a number of small synthetic communities. Competition seemed to dominate most of the communities, but with a weaker effect in SynComs displaying metabolically divergent bacteria. We identified a few bacteria apparently able to feed on other’s exudates; notably an Achromobacter sp. Finally, results suggest that cross-feeding is frequent, but potentially masked by strong, contact-dependent competition.

Soutenance de thèse de Victor Mataigne (Université de Rennes 1, ECOBIO, OSUR)

Observatoire des Sciences de l’Univers de Rennes (OSUR),Université de Rennes 1,Salle de conférence Observatoire des Sciences de l’Univers de Rennes (OSUR), Université de Rennes 1, Campus de Beaulieu, Bâtiment 14B, Salle de conférence Rennes Jeanne d’Arc – Longs Champs – Beaulieu Ille-et-Vilaine


Dates et horaires de début et de fin (année – mois – jour – heure) :
2021-12-08T09:00:00 2021-12-08T12:00:00