Unlike most organisms where a single cell carries a single nucleus, a single cell of an arbuscular mycorrhizal fungus contains thousands of nuclei. This mysterious multinucleate cell biology has led to open questions in evolutionary biology. The fungi have been called "evolutionary scandals" because they are thought to have survived millions of years without sexual reproduction, contradicting the theory that the lack of sexual reproduction in eukaryotes –organisms in which each cell contains a nucleus – should lead to extinction.
Unique genetic organisation
Recent research has shown that arbuscular mycorrhizal fungi have a unique genetic organisation, with some of these fungi containing not one, but two genomes. Kokkoris: “Although we now know that variation exists in this genetic system, it is not known how this genetic diversity is established, whether this variation exists in the absence of sexual reproduction, and whether this variation affects nutrient trade across mycorrhizal networks.” Using high-resolution molecular methods and advanced microscopy techniques, Kokkoris will investigate whether the coexistence of two genomes results in sexual reproduction, and how carrying two genomes could have an effect on plant health and plant community assembly.
Arbuscular mycorrhizal fungi
80% of all land plants engage in symbiotic relationships with arbuscular mycorrhizal fungi. Multiple fungi simultaneously connect to the roots of multiple plants, forming so-called underground common mycorrhizal networks in which carbon and nutrients are exchanged. With his research, Kokkoris will challenge the prevailing dogma that these fungi are strictly asexual and that connecting individuals always provides benefits. Moreover, his research may open new avenues to increase the agricultural benefits of these fungi - for which they are often exploited by increasing crop yield and by protecting crops from soilborne pathogens - based on their nuclear organisation.
About the Starting Grant
The ERC uses the Starting Grants to support talented early-career scientists to carry out pioneering projects for a period of five years. A total of 408 early-stage researchers have been awarded ERC Starting Grants. More information can be found in ERC's press release.
Image description: Microscopy image showing the different nuclei in a cell. The images from this photo series have won a few worldwide awards, namely the NIKON small world award and Olympus image of the year award. The image was made by Vasilis Kokkoris.