DOMON domain-containing proteins control root development upon phosphate deficiency and ammonium stress by modulating iron dynamics

Phosphorous and nitrogen are the main nutrients limiting plant growth in natural and agricultural systems. Plants typically uptake phosphorous in the form of inorganic phosphate, whereas the main nitrogen sources are nitrate and ammonium. Roots show a high degree of developmental plasticity in response to nutritional stresses, directly influencing plant fitness and stress resilience. In Arabidopsis thaliana , phosphate deficiency and high levels of ammonium in the media triggers a strong inhibition of the primary root growth. This developmental response is initiated by the accumulation of apoplastic iron in specific cell types, which triggers the inhibition of meristem maintenance and cell elongation. In this report, we show that DOMON domain-containing proteins are key molecular players controlling root development upon phosphate deficiency and ammonium toxicity via iron dynamics.