Nitrogen Systemic Signaling: from symbiotic nodulation to root acquisition

Plant nutrient acquisition is tightly regulated both by resources availability and metabolic needs, implying the existence of communication between roots and shoots to ensure their integration at the whole plant level. In a new collaborative review between the Frugier team at IPS2 and the Ruffel team at BPMP (Montpellier), published by Gautrat et al. in Trends in Plant Sciences, we focus on systemic signaling pathways controlling nitrogen (N) nutrition, achieved either by the root import of mineral N and in legume plants through atmospheric N fixation by symbiotic bacteria inside dedicated root nodules. Using recent knowledge gained on the systemic regulation of N-fixing nodulation, notably in our team, we explored conserved features with systemic pathways regulating mineral N acquisition by roots. We additionally describe how these N-related systemic pathways integrate with other environmental factors such as phosphate, light, and CO₂ availability.

Figure. A model for the systemic regulation of symbiotic nitrogen fixing nodulation in legume plants