Microbes including Sphingomonas can improve plants’ tolerance to biotic and abiotic stresses and promote growth. Most Sphingomonas genes involved into biotic interactions with plants remain uncharacterized. This project aims to elucidate how different local Sphingomonas strains interact with three different model plants A. thaliana, barley and poplar under different conditions. This will involve bacterial genomes, bacterial and plant transcriptomics, and metagenomics.