A TNL receptor mediates microbiome feedbacks in Arabidopsis

Plant performance depends on the soil microbiome. While microbiome feedbacks are well documented, the mechanisms by which plants perceive and mediate these feedbacks remain unclear. We established a framework using two distinct microbiomes in the same soil that differently affect plant growth. Screening 410 Arabidopsis thaliana accessions revealed substantial variation in growth feedbacks, which we used for genome-wide association mapping to identify Mediator of Microbiome Feedback 1 (MMF1), an immune receptor. Characterisation in the reference accession Col-0 revealed that mmf1 mutants lack the differential growth feedbacks, have an altered root bacterial community, and fail to induce a defence-related transcriptional response observed in wild-type plants. The discovery of MMF1 implies that integration of microbial effector signals optimises host microbiome composition and immune status to enhance growth.