Plants recruit and nurture billions of microbes on their roots, the so-called root microbiome. In return, the root microbiome supports the plant by improving nutrient uptake, enhancing tolerance to environmental stress, and by providing protection against pests and diseases. Host microbiome research has emerged as a new imperative in Life Sciences. The realization that thousands of microbial species are an integral part of the biology of plant hosts and expand their genomic potential comes with great new opportunities for microbiome assisted agriculture. Exciting breakthroughs in this novel research field revealed that plants can "cry for help" from their root microbiota in response to leaf pathogen infection, or other types of stress, therewith alleviating the stress through microbiome encoded functions. These discoveries sparked a number of vital questions in host microbiome research: Which plant genes/traits optimize microbiomes for host-supporting health functions? What microbiome functions are recruited by stressed host plants and how do they improve plant performance? As part of your PhD research, you will investigate the molecular mechanisms of how plants recruit beneficial microbes to their root system in response to pathogen attack, and decipher which plant traits are involved in optimizing root microbiomes for improved host supporting health functions.