<i>Aeschynomene</i>'s shortcut: A receptor-like cytoplasmic kinase drives nod-independent nodule formation

Legume crops can grow without added nitrogen fertilizers thanks to a remarkable partnership with rhizobia, soil bacteria that fix atmospheric nitrogen within specialized root nodules.In most legumes, nodule formation is initiated when rhizobia release Nod factors, small signaling molecules that plant receptors recognize to start symbiotic development.But some tropical legumes, such as Aeschynomene evenia, defy this rule: they form nitrogen-fixing nodules without recognizing Nod factors (Chaintreuil et al. 2018), partnering with photosynthetic Bradyrhizobium strains that live in flooded tropical soils.How these plants detect and accept their bacterial partners without the classical Nod factor signal has fascinated researchers for decades.