Phloem-Mobile Negatively Regulates Expression of in Arabidopsis Roots.

Phosphorus (P) is an essential plant macronutrient; however, its availability is often limited in soils. Plants have evolved complex mechanisms for efficient phosphate (Pi) absorption, which are responsive to changes in external and internal Pi concentration, and orchestrated through local and systemic responses. To explore these systemic Pi responses, here we identified as a phloem-mobile mRNA, an Arabidopsis homolog of , that is responsive to the Pi-starvation stress.