Résumé
Nitrogen fixation in the legume-rhizobium symbiosis is a crucial area of research for more sustainable agriculture. Our knowledge of the plant cascade in response to the perception of bacterial Nod factors has increased in recent years. However, the discovery that Nod factors are not involved in theAeschynomene-Bradyrhizobiumspp. interaction suggests that alternative molecular dialogues may exist in the legume family. We evaluated the conservation of the signaling pathway common to other endosymbioses using three candidate genes:Ca²⁺/Calmodulin-Dependent Kinase(CCaMK), which plays a central role in cross signaling between nodule organogenesis and infection processes; andSymbiosis Receptor Kinase(SYMRK) andHistidine Kinase1(HK1), which act upstream and downstream ofCCaMK, respectively. We showed that CCaMK, SYMRK, and HK1 are required for efficient nodulation inAeschynomene evenia. Our results demonstrate that CCaMK and SYMRK are recruited in Nod factor-independent symbiosis and, hence, may be conserved in all vascular plant endosymbioses described so far.