The SYM team is interested in the association between the actinobacteria Frankia and actinorhizal plants.

This association, which takes the form of root nodules, is a facultative mutualistic symbiosis with reciprocal benefits: the bacterium fixes atmospheric nitrogen for the plant and receives carbon substrates in return. This symbiosis represents an original model of plant/microorganism interactions (Frankia is the only actinobacterial able to fix nitrogen during symbiosis). In addition, it is a complex model, particularly in terms of the symbiotic mechanisms involved (We still have no information about nodulation genes in Frankia and recognition/signaling mechanisms are still poorly elucidated).

The model host plant belong to the Alnus genus. These are mainly the A. glutinosa species, and the two montane/alpine species A. incana and A. viridis. Whatever the diversity of ecosystems in which these species are present, the Alnus/Frankia complex has the potential to have a major impact on their functioning. We are working on two themes to understand (i) the mechanisms of actinorrhizal interaction and (ii) the evolution and ecology of this symbiosis. The multidisciplinary approaches we are developing offer a fascinating vision of this symbiosis, in all its facets, by combining skills in various fields, from bacteria to plants, from ecology to genomics, from physiology to metabolomics.