Doctoral defence: Yiming Meng "Plant mycorrhizal type and status in the global flora"

On November 8 at 10:15 Yiming Meng will defend her doctoral thesis "Plant mycorrhizal type and status in the global flora" for obtaining the degree of Doctor of Philosophy (in Plant Ecology and Ecophysiology).

Supervisors:
RyC Researcher Carlos Guillermo Bueno González, Pyrenean Institute of Ecology - CSIC, Spain
Associate Professor John Alexander Davison, University of Tartu
Professor Maarja Öpik, University of Tartu

Opponent:
Associate Professor Justine Karst, University of Alberta, Canada

Summary
Plants and fungi have been collaborating for millions of years through a partnership called mycorrhiza, a symbiotic relationship where both benefit. The symbiosis varies among plants, with different species forming functionally different associations with different fungi (plant mycorrhizal types); and varying in their reliance on these associations: always, sometimes or never (plant mycorrhizal status). Despite mycorrhizal symbiosis being critical for plant performance and ecosystem functioning, direct evidence about mycorrhizal type and status exists for <5% of world’s plants. In this thesis, I found that plant mycorrhizal type is largely influenced by evolutionary history (phylogeny), while plant mycorrhizal status is more affected by environmental conditions they occupy. Focusing on an unstudied region in the Andean Paramo, the distributions of plant mycorrhizal types and statuses with elevation contrasted with patterns in the northern hemisphere, perhaps reflecting the different elevational ranges or the specific ecological conditions. I found that prediction of mycorrhizal type and status for unstudied plant species can be improved by incorporating plant phylogeny, the environments they occur in, and other plant traits (e.g. morphology). My thesis also investigated mycorrhizal associations from a fungal perspective. I found that plants sometimes mycorrhizal are more selective in choosing fungal partners than those always mycorrhizal, suggesting they may better select fungi offering specific benefits. By reanalysing existing data, I also showed that plants with different functional characteristics, including plant mycorrhizal statuses, associate with fungal communities that differ in diversity. In conclusion, this thesis improves our understanding of plant-fungi interactions, highlighting the importance of evolutionary and ecological factors for predicting and interpreting mycorrhizal associations, with implications for ecosystem management and conservation.