Format: ORAL

Lauri Laanisto

Chair of Biodiversity and Nature Tourism, Estonian University of Life Sciences, Tartu, Estonia

Mycorrhizal symbiosis is an ancient association between plants and fungi, crucially important especially for woody plants, as they have to maintain aboveground structures. Our current understandings of how woody plants respond to abiotic stress and how mycorrhiza mitigates this stress is very limited and considers almost exclusively just a single stress factor at a time. Functional diversity of both woody plants and mycorrhizal fungi interacting with them, variability of the strength and composition of multiple stress conditions in different regions of the world all this makes it difficult to predict the patterns of these interactions from both the adaptational and mitigational point of view. In this study we used top-down approach, where known interactions are partitioned into functional and biogeographical groups, and then the stress tolerances and interactions are mapped into overlapping heatmaps to provide us large-scale patterns of these associations. We compiled a concordant dataset of 621 woody species stress polytolerance (including shade, drought, waterlogging, cold stress) and their known species-specific mycorrhizal interactions. We tested how stress polytolerance correlates with different mycorrhiza functional types. Our results confirmed contrasting patterns between single vs. multiple type, arbuscular vs. ectomycorrhiza, and obligate vs. facultative mycorrhizal interaction. Functionally different symbionts form significantly polarizing abiotic stress mitigation patterns with woody species with different life forms, growth forms, and biogeographical origin. These results provide insight into both evolutionary and biogeographic patterns related to the development of plant-mycorrhiza interactions.