Year: 2026
Type: preprint
Abstract: Bradyrhizobia are widely used as plant growth promoters in agriculture, yet their cell biology remains poorly understood. Here, we described for the first time, nucleoid segregation dynamics and the cell cycle of Bradyrhizobium at the cellular level. We show that highly asymmetric polar growth generates a short daughter cell and a longer mother cell at each division. Nucleoid compaction and positioning change across growth phases, culminating in a highly compacted, asymmetrically positioned nucleoid in stationary phase. ParB presents a subpolar localization, at the nucleoid periphery. Despite this pronounced cellular asymmetry and the presence of a single large chromosome, chromosome conformation capture reveals a global chromosome organization similar to that of bacteria undergoing conventional binary fission Together, these findings uncover a distinctive cell cycle program in Bradyrhizobium. showing that such extreme asymmetry in growth and division, significantly different from closely related characterized α-Proteobacteriota, is compatible with conserved principles of chromosome organization.
Institutions: Consejo Nacional de Investigaciones Científicas y Técnicas, National University of General San Martín, Instituto de Biotecnología y Biología Molecular, Universidad Nacional de La Plata, Centre National de la Recherche Scientifique, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, Institut de Biologie Intégrative de la Cellule
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7225434042