Judith Felten, group leader at UPSC and Assistant Professor at the Swedish University of Agricultural Sciences, talks about the knowns and unknowns of the fascinating mechanism that allows roots and fungi to form a beneficial relationship (symbiosis). The fungus provides soil-nutrients to the tree and receives photosynthetic sugars from the tree. Like this both partners benefit from each other and stimulate each other’s growth. The lecture is held in English with Swedish subtitles.