Nanobody-driven signaling reveals the core receptor complex in root nodule symbiosis

Understanding the composition and activation of multicomponent receptor complexes is a challenge in biology. To address this, we developed a synthetic approach based on nanobodies to drive assembly and activation of cell surface receptors and apply the concept by manipulating receptors that govern plant symbiosis with nitrogen-fixing bacteria. We show that the Lotus japonicus Nod factor receptors NFR1 and NFR5 constitute the core receptor complex initiating the cortical root nodule organogenesis program as well as the epidermal program controlling infection. We find that organogenesis signaling is mediated by the intracellular kinase domains whereas infection requires functional ectodomains. Finally, we identify evolutionarily distant barley receptors that activate root nodule organogenesis, which could enable engineering of biological nitrogen-fixation into cereals.

Automated summary

This study developed a synthetic approach using nanobodies to understand and activate multicomponent receptor complexes, successfully manipulating receptors involved in plant symbiosis with nitrogen-fixing bacteria. The authors found that the Lotus japonicus Nod factor receptors NFR1 and NFR5 form the core receptor complex for initiating root nodule organogenesis and controlling infection. They also discovered that organogenesis signaling is mediated by intracellular kinase domains, while infection requires functional ectodomains. Additionally, evolutionarily distant barley receptors were identified, which could potentially enable nitrogen-fixation engineering in cereals.