This poster was presented during the 7th Plant Genomics and Gene Editing Congress: Europe 21-22 May 2019. ABSTRACT Background: Biocontrol agents and beneficial microbes are used in integrated pest management and help to secure crop yields without negative effects on the environment. Endophytic microbes can increase the stress tolerance of their host plants and enhance host performance against pathogens. Reports from the last decades indicate that the endophytic fungus Acremonium alternatum can control foliar pathogens (mildew, tar spot) but the mechanism behind this was not clear. Research question: Our goals were to (1) identify the molecular mechanisms behind the biocontrol action of A. alternatum against root and leaf pathogens and (2) assess general plant performance with the endophyte under stress conditions. Results: For the root pathogen Plasmodiophora brassicae (clubroot) we found that A. alternatum reduced clubroot symptoms by 30%. The endophyte established systemic acquired resistance in clubroot-infected roots and delayed pathogen development. In addition, the fungus enhanced reproductive success and survival of clubroot-inoculated plants. For the foliar pathogen Botrytis cinerea (grey mould) we found that A. alternatum reduced lesion size by 50 % and 70 % when applied on leaves directly or indirectly through soil. The endophyte also increased salt stress tolerance in plants grown in axenic culture. Outlook: We started to look at performance of specific crops (oilseed rape, tomato, wheat, corn) for their response to A. alternatum under stress conditions. For the near future we look for solutions to (1) further elucidate which molecular markers are crucial for the biocontrol effect of the fungus against pathogens using RNAseq and –omics techniques, (2) acquire funding and cooperation partners to carry out field-trial like experiments with natural soils to confirm our findings from greenhouse trials, (3) find partners interested to develop with us a formulation for a crop-suitable application of this fungus.