||In an ecosystem in which organisms are challenged with adverse conditions, the ability to respond is crucial to survive. Many studies focus on how environmental shifts lead to adaptations in a single species. Despite the fact that virtually all species are involved in
mutualistic associations and mutualistic partners affect each other's phenotype, the biotic context of organisms is, however, rarely taken into account. In this project we aim at documenting ionizing radiationinduced changes in pine trees and their rhizosphere microbiome
exposed to the extreme environmental stress resulting from the Fukushima Dai-Ichi nuclear accident. We will assess taxonomic and functional diversity of the bacterial and fungal rhizosphere communities, phenotypic and genetic diversity of pioneer ectomycorrhizal fungi, environmental adaptation and mechanisms of phenotypic plasticity in pines, and the potential of ectomycorrhizal species to shield their pine host from selective pressure. The results
of the proposed research will contribute to a theoretical framework for adaptation in mutualistic systems which is paramount for understanding the impact of human-induced abiotic change on biodiversity. Furthermore it will lead to novel insights into radionuclides detoxification and the mechanisms used for adaptation to long-term ionizing radiation. An enhanced knowledge on radionuclide adaptation is urgently needed as a scientific basis for
risk assessment in chronic exposure conditions.