Biological nitrogen fixation

Leguminous plants play a crucial role in natural ecosystems as well as in agriculture. They contribute one third of the dietary protein nitrogen needs of the world’s population and account for over 27% of primary crop production. Perhaps the most distinguishing feature of legumes is their natural ability to acquire nitrogen from the air through symbiotic interaction with a group of soil bacteria collectively called rhizobia.

Nitrogen is the critical limiting element for growth of most plants and is a building block of all life, being part of nucleic acids, amino acids and proteins. Consequently, the nitrogen-fixing symbiosis confers a clear advantage under nitrogen-limiting conditions and a better understanding of the process is expected to benefit worldwide food supply as well as the environment. 

Rhizobia can trigger host plants to form root nodules, specialized organs that offer the bacteria an exclusive ecological niche in which they reduce atmospheric dinitrogen to ammonia. Ammonia is made available to the plant, which in turn provides carbon sources to the bacteria.

Research within our group is aimed at achieving a better survival of rhizobia during inoculant production and seed coating. More specifically, we investigate molecular mechanisms of desiccation tolerance in rhizobia and apply this knowledge to improve seed coating strategies and improve biological nitrogen fixation.