Maria P. Fernandez
I am professor at the university of Lyon , France . I am working in the field of Microbial Ecology and particularly the relationships between plants and N2- fixing bacteria. During my phD (1984) I worked on Legumes-rhizobia using 15N and 14C isotopes for understanding the distribution of fixed N within the host plant and the carbon cost of nitrogen fixation. Later I shifted to actinorhizal symbiosis involving the actinobacteria Frankia. I was doing my research on (1) taxonomy, diversity and evolution of Frankia using both physiological methods, molecular biology, biochemistry and on (2) symbiotic mecanisms of host-Frankia specificity using metabolomic and genetic approaches. In the recent years I was working on a unique Frankia model capable of in planta sporulation (Sp+ phénotype)associated with alder species (Alnus). I studied the diversity and distribution of these strains, their specificity toward the host genera and their role in natural ecosystems. These uncultured strains are supposed to be obligate symbionts. We demonstrated that sp+ strains are genetically different from Sp- strains, are more specific and have higher occurrence on Alnus species and subspecies distributed in alpine/boreal climats.