Legume Symbiotic Interaction from Gene to Whole Plant

Bacterial and arbuscular mycorrhizal symbiosis are both beneficial for bacteria or fungus and host plants. The bacterial symbiosis enhances plant growth and productivity and it is beneficial for sustainable agriculture. In fact, rhizobia are soil bacteria that form symbiosis with legumes and help in fixing atmospheric nitrogen by converting into ammonia inside the root nodules. Legumes-rhizobia interaction is specificity controlled by various genetic and molecular mechanisms. Here we review the different components and molecules implicated in this interaction. Moreover, we detailed the genes coding for Nod factor secreted by bacteria and their receptors present on the cell membrane of plant host. The perception of Nod factors by their receptors leads to activate various signaling pathways that involve different transcription factors depending on the symbiotic stage. Nodule inception NIN proteins are crucial for nodulation organogenesis through the activation of target proteins. Finally, we reviewed the response of rhizobia and plants to environmental stress and their strategy to adapt stress.