The sustainability of agri-food production passes also through specific bacteria that are in symbiosis with plants and are capable of transforming atmospheric nitrogen into ammonium, making chemical fertilizers unneeded. A study by the Department of Biology explains why symbiosis works better with certain bacteria than with others.
Caption: Alfalfa plants in symbiosis with different rhizobia (in the middle, an ineffective symbiont, on either side effective symbionts)
Bacteria can help to achieve sustainable agriculture. Certain types of bacteria, in fact, called rhizobia, are able to fertilize in a natural way the plants with which they come into symbiosis. They transform atmospheric nitrogen into ammonium and allow the main leguminous crops (beans, chickpeas, lentils, but also alfalfa) to grow in poor soils, without any need for chemical fertilization.
But not all bacteria are the same: only some types of rhizobia present in the soils achieve effective symbiosis with leguminous plants. The reason for this is a research published in mSystems, the journal of the American Association for Microbiology (“Nonadditive Transcriptomic Signatures of Genotype-by-Genotype Interactions during the Initiation of Plant-Rhizobium Symbiosis” DOI: 10.1128/mSystems.00974-20). The study led by Alessio Mengoni, Camilla Fagorzi and Giovanni Bacci of the Department of Biology clarifies that specific bacterial genes for a good symbiosis “light up” only in the presence of certain plant varieties. Mapping those genes will allow the selection of the most suitable rhizobia, with the result of having a “custom symbiont”, then making agricultural productions with low environmental impact.
The study, carried out with the support of the Advanced Genomics Laboratory thanks to the funds received from the Department of Biology as a department of excellence 2018-2020 selected by the Ministry of University and Research, has also benefited from the support of the Fondazione CR Firenze and is part of the MICRO4Legumes research project (Ministry of Agricultural, Food and Forestry Policies).
