The Lys-motif receptor LYK4 mediates Enterobacter sp. SA187 triggered salt tolerance in Arabidopsis thaliana

Microbes of the root-associated microbiome contribute to improve resilience and fitness of plants. In this study, the interaction between the salt stress tolerance-inducing beneficial bacterium Enterobacter sp. SA187 and Arabidopsis was investigated with a special focus on the plant immune system. Among the immune signalling mutants, the Lys-motif receptors LYK4 strongly affected the beneficial interaction. Overexpression of the chitin receptor components LYK4 compromised the beneficial effect of SA187 on Arabidopsis. Transcriptome analysis revealed that the role of LYK4 in immunity is intertwined with a function in remodeling defense responses. Overall, our data indicate that components of the plant immune system are key elements in mediating beneficial metabolite-induced plant abiotic stress tolerance. Examination of the effect of the beneficial bacterium Enterobacter sp. SA187 on Arabidopsis thaliana plants under control conditions and salt stress in WT, lyk4 and LYK4-OE genotypes