Editing Calmodulin (section)

====Nodule formation====
Ca<sup>2+</sup> plays an important role in nodule formation in legumes. Nitrogen is an essential element required in plants and many legumes, unable to fix nitrogen independently, pair symbiotically with nitrogen-fixing bacteria that reduce nitrogen to ammonia. This legume-''[[Rhizobium]]'' interaction establishment requires the Nod factor that is produced by the ''Rhizobium'' bacteria. The [[Nod factor]] is recognized by the root hair cells that are involved in the nodule formation in legumes. Ca<sup>2+</sup> responses of varied nature are characterized to be involved in the Nod factor recognition. There is a Ca<sup>2+</sup> flux at the tip of the root hair initially followed by repetitive oscillation of Ca<sup>2+</sup> in the cytosol and also Ca<sup>2+</sup> spike occurs around the nucleus. DMI3, an essential gene for Nod factor signaling functions downstream of the Ca<sup>2+</sup> spiking signature, might be recognizing the Ca<sup>2+</sup> signature. Further, several CaM and CML genes in ''[[Medicago]]'' and ''Lotus'' are expressed in nodules.