Plants constantly interact with a wide range of microorganisms, varying from devastating pathogens to beneficial symbionts. This diverse microbial environment is an extensive evolutionary driving force, to a great extent shaping plant diversity and distribution. Hypothesizing on evolutionary relations between symbiosis and pathogenesis we can assume that symbiotic interactions arose from plant-pathogen interactions, as a more common type of relationship. When the coevolution of two organisms eventually resulted in a mutually beneficial interaction. One of the most intimate plant mutualistic interactions is a symbiosis between Legumes and nitrogen-fixing bacteria, collectively called rhizobia. Legume plants accommodate rhizobia in special organs, the root nodules, provide with carbon and receive nitrogen in return.
Although, root nodule symbiosis is one of the most productive nitrogen-fixing systems with a great potential for sustainable agriculture its efficiency can be highly variable. What restricts its efficiency? Combining phylogenetic, transcriptomic and genetic approaches, we aimed to identify mechanisms negatively regulating root nodule symbiosis development and nitrogen fixation, evolutionarily co-opted from molecular mechanisms of plant defence against pathogens. The discovery of symbiosis-restricting factors will help to unlock the full potential of symbiotic nitrogen fixation and serve as a basis for further studies on Legume-rhizobia symbiosis and its improvement in legume crops, an integral part of sustainable agricultural systems.
If you are interested in our research and would like to join, please contact Aleksandr Gavrin.