Rhizobial symbiosis articles from across Nature Portfolio

Engineering the form and function of root systems and their associated microbiota could provide a means to mitigate adverse climate-driven effects. Here, the authors review the recent developments in plant and rhizobacterial synthetic biology and highlight engineering targets for applications in root systems and rhizosphere.

The authors show IRON MAN peptides have an essential role in symbiotic nitrogen fixation during legume-rhizobium symbiosis. The peptides additionally function to regulate nitrogen homeostasis by controlling nitrogen-iron balance.

Engineering ammonium excretion diazotrophs suffers from severe penalties to the bacteria. Here, the authors utilize a thermo-sensitive glutamine synthetase-based regulatory switch that permits diurnal changes in diazotrophic lifestyle, coincident with seasonal temperatures for cereal cultivation.

The authors use single-cell analysis to identify genes specifically expressed in plant root cells that respond to infection by nitrogen-fixing rhizobia. They show that one of these genes, SYMRKL1, is required for normal progression of infection.

Single-nucleus transcriptomes uncover cell type-specific gene reprogramming in response to nod factors in Medicago, including a defence response at 30 min, which largely returned to normal at 6 h. The results reveal that MtFER interacts with LYK3 and regulates rhizobial symbiosis.

Philip Poole narrates his career story and his motivations for studying rhizobia, the agriculturally important bacterial plant symbiont responsible for fixing nitrogen.

Single-nucleus transcriptomic analysis of Medicago roots reveals dynamic cell-specific responses to the Nod factor — a bacterially secreted chito-lipopolysaccharide with a key role in the root nodule symbiosis between legumes and rhizobia — and identifies the receptor-like kinase FERONIA as a phosphorylation target of the Nod factor receptor LYK3, which together function to control nodule formation and bacterial infection.

Transcriptomics of nitrogen-fixing plants and their symbionts reveals the origins of root-nodulating symbiosis and how it has endured more in some groups than others

Various clades of legume plants irreversibly modify the development of their symbiotic nitrogen-fixing microorganisms. Key transcription factors controlling this process have been identified. They are conserved and functional even in plant species that do not induce such a terminal differentiation.

Duplication of KCBP, which encodes a plant-specific microtubule-based kinesin motor, occurs solely in legumes of the clade that form symbiosomes. The nodule-enriched KCBP (nKCBP) is co-opted by rhizobia to control central vacuole morphogenesis in symbiotic cells, thus achieving symbiosome development and nitrogen fixation.