Nod factor recognition at root epidermis and its impact on microbiota assembly in Lotus japonicus
S. RADUTOIU (1), E. Murakami (2), R. Zgadzaj (3), R. Garrido Oter (3), J. Cheng (4), K. Gysel (4), L. Madsen (4), J. Stougaard (4), P. Schulze-Lefert (3) (1) Department of Molecular Biology and Genetics, Aarhus University, Denmark, Denmark; (2) Department of Molecular Biology and Genetics, Aarhus University, Denmark; (3) Max Plack Institute for Plant Breeding, Cologne, Germany; (4) Department of Molecular Biology and Genetics, Aarhus University, Denmark

Protein-carbohydrate recognitions are central molecular events in host-microbe interactions. Legumes use LysM proteins to recognize carbohydrates produced by pathogens and symbionts. This suggests that an ancient recognition process has been used in legumes for evolution of elaborated mechanisms for various carbohydrate perceptions. In Lotus japonicus two LysM receptor kinases, NFR1 and NFR5, initiate root nodule formation and rhizobial infection after perception of Nod-factors secreted by M. loti. Lotus encodes for additional 17 LysM receptors. We used reverse genetics coupled with gene expression and in planta functional studies, and have identified a novel component involved in Nod factor signaling that contributes to the symbiotic interaction between Lotus and its nitrogen-fixing symbiont. To understand how the capacity of Lotus to recognize Nod factors and to initiate a nodulation pathway influences its ability to associate with other bacteria, we performed a comparative analyses of microbiota associated with soil-grown wild-type and symbiotic mutant plants. Community profiling of 16S rRNA gene amplicons identified a previously unsuspected role of the nodulation pathway in the establishment of distinctive bacterial assemblages in root and rhizosphere. These findings imply a role of the legume host in selecting a broad taxonomic range of root-associated bacteria that, in addition to nitrogen-fixing rhizobia, may have an impact on plant growth and ecological performance.

Abstract Number: P5-1
Session Type: Plenary