A major challenge for mankind is to feed the increasing human population in a sustainable manner. The UN’s Sustainable Development Goals aim to end hunger and malnutrition by 2030. Improvement of sustainable crop production is a critical element of achieving these ambitious goals. Currently, more than one third of crop yields are lost due to abiotic and biotic stress factors such as drought, salinity, pests and diseases. To minimize these yield losses and to simultaneously reduce the environmental impact of current agricultural practices, future crop production needs to be achieved on sub-optimal soils with reduced input of fertilizers and pesticides (‘more with less’). The goal of our project is to explore and exploit the functional potential of beneficial bacteria that live inside plant roots (endophytes) to protect plants from fungal infections. Plants are colonized by an astounding number of microorganisms that can have profound effects on seed germination, seedling vigor, plant growth and development, nutrient acquisition, disease resistance, abiotic stress tolerance and yield. Thus, the microbiome provides a number of essential lifesupport functions to plants. In return, plants transfer a substantial part of their photosynthetically fixed carbon to their microbial partners in order to support their beneficial activities. To date, the taxonomic diversity of root-associated microbiomes has been characterized in great detail. For the vast majority of microorganisms that live inside plant root tissue (i.e. the endophytic root microbiome), however, the functional potential and the mechanisms underlying the molecular and chemical dialogues between<br/>endophytes and plant root tissue are still largely unknown. Endophytic microbes have specific traits that allow them to enter and proliferate in the internal plant root tissue and have sophisticated ways to modulate the gatekeeping role of the plant root immune system. Due to this intimate association with the host plant,<br/>endophytic microorganisms are considered as ‘high potentials’ for the development of microbiome-based products for plant growth promotion and plant protection. Hence, a critical step in developing new microbiome-assisted approaches to quantitatively and predictably improve crop resilience, is to unwire the largely unknown beneficial functions and regulatory networks in the interactions between the endophytic root microbiome and its host plant. To that end, we will develop and integrate cutting-edge technologies and state-of-the-art approaches in microbiology, molecular biology, genomics, bioinformatics, chemistry, and microscopy to explore the rich genomic and chemical diversity of the endophytic root microbiome and its communication with the plant. Translation and implementation of this new fundamental scientific knowledge will aid in the selection of plant and microbial traits to improve the sustainability of future crop production.