LAUSR

Significance Most legumes benefit from nodulation, an ecologically and agriculturally important symbiosis with nitrogen-fixing bacteria. This endosymbiosis requires the formation of unique transcellular structures that mediate bacterial entry into root cells. Comparisons have been drawn between the subcellular structures that form during infection and those that precede cell division, but the evidence remains circumstantial. Here, we functionally link a deeply conserved mitotic module consisting of Aurora kinase, its regulators, and its targets to the symbiotic infection process. We propose that the recruitment of cell cycle machinery to nodulation is to promote the transcellular deposition of cell wall material, a feature common to infection and cell division. This progress provides a crucial entry point toward understanding the mechanisms that underlie endosymbiotic infection.