I started to work on plant-bacteria interaction seven years ago during my PhD in Florence, studying the genetic diversity of the whole bacterial community in soil and plant tissues of Medicago sativa at different taxonomic levels (1).
After my PhD, I spent another year in Florence working on different projects: the research of common features within Alphaproteobacteria interacting with plants (2) and on the phylogeny of the gene nreB, which encodes for a Ni/H+ antiporter, investigating its role in Sinorhizobium meliloti that is a nickel-sensitive species (3).
Then I moved to the Interdisciplinary Research Institute (IRI-CNRS) in Lille (France) where I worked on the S. meliloti cell cycle regulation and on its connection with bacteroid differentiation inside plant’s nodules (4).
Here in Oxford I’m working on the analysis of root secretion using a rhizobial Lux biosensor library. For a long time the rhizosphere has been seen as a black box, little is known about the variation of root exudates in space and time. Indeed, plants release up to the 20% of carbon photosynthates as mucillages and other compounds, which actively modify the zone close to the roots. This creates a different environment with respect to the bulk soil and shapes the bacterial community that resides there. Now it is possible to depict the secretome of different plants using Rhizobium leguminosarum strains engineered to detect variation in the secretion of different metabolites. This information will allow us to draw, for the first time, a spatial and temporal map of root exudates.
1. Pini, F., Frascella, A., Santopolo, L., Bazzicalupo, M., Biondi, E.G., Scotti, C. & Mengoni, A. (2012) Exploring the plant-associated bacterial communities in Medicago sativa L. BMC Microbiology 12(1):78.
2. Pini, F., Galardini, M., Bazzicalupo, M. & Mengoni, A. (2011) Plant-bacteria association and symbiosis: are there common genomic traits in Alphaproteobacteria? Genes 2(4):1017-1032.
3. Pini, F., Spini, G., Galardini, M., Bazzicalupo, M., Benedetti, A., Chiancianesi, M., Florio, A., Lagomarsino, A., Migliore, M., Mocali, S. & Mengon, A. (2014) Molecular phylogeny of the nickel-resistance gene nreB and functional role in the nickel sensitive symbiotic nitrogen fixing bacterium Sinorhizobium meliloti. Plant and Soil, 377:1-13.
4. Pini, F., Frage, B., Ferri, L., De Nisco, N.J., Mohapatra, S.S., Taddei, L., Antonella Fioravanti, A., Dewitte, F., Galardini, M., Brilli, M., Villeret, V., Bazzicalupo, M., Mengoni, A., Walker, G.C., Becker, A. & Biondi, E.G. (2013) The DivJ, CbrA and PleC system controls DivK phosphorylation and symbiosis in Sinorhizobium meliloti. Molecular Microbiology 90(1):54-71.
This work is funded by the BBSRC