Harnessing omics to decode the mechanisms of symbiotic nitrogen fixation

Symbiotic nitrogen fixation is predominantly observed in legumes, which form specialized structures termed nodules on their roots that contain symbiotic rhizobia. This mutualistic association provides reciprocal benefits: rhizobia convert atmospheric nitrogen into bioavailable forms, supplying essential nitrogen to their host plants, while obtaining reduced carbon in return. The increasing reliance on nitrogen fertilizers to satisfy escalating demands for food has prompted various approaches aimed at unravelling the mechanisms underlying symbiotic nodulation, seeking to transfer this capacity to non-nodulating crops. Transcriptome-based analyses have revealed that nodulation is a complex developmental program involving many genes. To comprehensively investigate this phenomenon, multiple omics technologies have been deployed and integrated, yielding exciting breakthroughs. In this review, we outline how omics have accelerated research in this area and discuss how advancements in technologies, such as artificial intelligence, could further deepen our understanding of nodulation.