Phosphate sensing in root development

Phosphate (Pi) and its anhydrides constitute major nodes in metabolism. Thus, plant performance depends directly on Pi nutrition. Inadequate Pi availability in the rhizosphere is a common challenge to plants, which activate metabolic and developmental responses to maximize Pi usage and acquisition. The sensory mechanisms that monitor environmental Pi and transmit the nutritional signal to adjust root development have increasingly come into focus. Recent transcriptomic analyses and genetic approaches have highlighted complex antagonistic interactions between external Pi and Fe bioavailability and have implicated the stem cell niche as a target of Pi sensing to regulate root meristem activity.

► Inadequate phosphate availability to plants is sensed at the systemic and local level.
► External phosphate concentration is sensed in conjunction with Fe bioavailability.
► Transcription factor PHR1 integrates responses to phosphate and iron bioavailability.
► External phosphate controls locally root meristem activity via the stem cell niche.
► First components in local phosphate sensing have been indentified, LPR1 and PDR2.