A mycorrhizal revolution: the role of diverse symbiotic fungi in modern terrestrial ecosystems
The colonisation of the landmasses by plants >500 Mya was a major turning point in Earth’s history, drastically altering the development of the biosphere and providing the basis for all terrestrial life ever since. The hypothesis that early plants were facilitated in their invasion of the land environment by forming symbioses with arbuscular mycorrhizal fungi (AMF) is widely supported by fossil and molecular evidence. My previous findings in physiology identified the role of AMF as a driving force in evolution by supporting growing nutrient demands of increasingly large plants, against a background of declining atmospheric CO2. 
Recently, it was revealed that the earliest groups of extant plants form symbioses with a different group of fungi - Mucoromycotina “fine root endophytes” (MFRE) and I have since shown that MFRE symbioses are nutritionally mutualistic. These findings support a new hypothesis: the earliest land plants had a wider range of symbiotic options than was previously thought with MFRE also playing an important role in their supply of nutrients. I have now discovered that MFRE symbioses are not limited to early divergent plants, but instead span the entire land plant phylogeny. Coupled with my most recent findings that MFRE symbionts are distinct from AMF in terms of function and responses to changing atmospheric CO2 concentrations, these discoveries call into question much of what we thought we knew about plant-fungal symbioses. Much of the fundamental biology of MFRE remains unknown, preventing us from understanding the true complexity of plant-fungal symbioses, how they might respond to environmental change and their potential exploitation. This project will address the fundamental knowledge gaps surrounding the diversity, structure and functional significance of plant-MFRE symbioses, paving the way for a revolution in mycorrhizal research in the 21st century.