Centre for Plant Sciences

Dr Katie Field

mail: k.field@leeds.ac.uk

Plant-fungal symbioses; plant-soil processes; sustainable agriculture; evolutionary ecophysiology

Plant-fungal symbioses and their applications in sustainable agriculture

Today, it is estimated that more than 80% of land plants, representing over 90% of plant families, form nutritional symbioses with soil-dwelling fungi. These associations are known as ‘mycorrhiza’, or ‘mycorrhiza-like’ in plants without roots. Through these associations, plants assimilate fungal-acquired mineral nutrients from beyond root depletion zones. In return, plants supply their fungal partners with carbohydrates fixed from atmospheric carbon dioxide through photosynthesis.

Many key crop species have been shown to be able to form mutualistic symbioses with arbuscular mycorrhizal fungi. This is leading to the development of novel approaches in crop breeding and agricultural practices, encouraging the formation of mycorrhizal associations and utilisation of previously plant-inaccessible phosphorus pools. Fundamental research on various wild plant species has shown that the efficiency by which plant-fixed carbon is exchanged for fungal-acquired nutrients is affected by environmental perturbation, such as CO2 concentration. By using combined ecophysiology, metabolomics and isotope tracer techniques, my research aims to expand our understanding of crop-mycorrhiza-environment interactions with important applications in sustainable agriculture.

Evolutionary ecophysiology

How did the biotic and abiotic environments interact to drive plant evolution and the development of the terrestrial biosphere?

This key question underpins my research into the interactions between ancient land plant lineages and symbiotic soil fungi.  Plant-fungal symbioses date back to when plants first colonized Earth’s landmasses more than 475 million years ago.

Through the Palaeozoic, CO2 concentrations declined dramatically. This was largely being driven by, and provides the backdrop for, diversification of the terrestrial flora with plants increasing in number, stature, morphological complexity and demand for inorganic carbon. Fossil and molecular evidence suggest that the earliest plants to emerge onto the land were likely similar to modern-day liverworts. As such, these tiny plants provide an excellent opportunity for us to understand how mycorrhiza-like associations in the earliest plants may have facilitated plant domination of the terrestrial biosphere. Recent findings show that the earliest plants may not have associated with mycorrhizal fungi of the Glomeromycota as has been hitherto assumed, instead fungi of the Mucoromycotina may well have been key players in plant terrestrialization.

We are only just starting to understand the diversity, structure and physiological function of the relationships between early branching lineages of land plants and their symbiotic fungi. We aim to shed new light on the role fungal symbionts may have played in the development of Earth’s ecosystems.


fie1Schematic diagram showing carbon-for-nutrient exchange between plants and mycorrhizal fungi.

fie2Basal liverwort Haplomitrium gibbsiae in experimental isotope tracing system for determining carbon-for-nutrient exchange between liverworts and symbiotic fungi.