Multifaceted role of autophagy in regulating phosphate homeostasis and developmental root plasticity.

Macroautophagy/autophagy delivers cytoplasmic constituents to the lysosome/vacuole for degradation and recycling, wherein regulates diverse aspects of cellular homeostasis. However, more is needed to know how autophagy activity is fine-tuned at the organismal level to optimize plant fitness in response to developmental and environmental cues. We recently revealed that both basal autophagy and phosphate (Pi) starvation-induced autophagy are required to maintain Pi homeostasis by modulating the expression of PHOSPHATE TRANSPORTER 1 (PHT1) Pi transporters. While Pi limitation preferentially increases the number of autophagic structures and the autophagic flux in the differential zone of the Arabidopsis primary root, Pi starvation-induction of ATG8f and ATG8h expression contributes to the control of autophagic flux in the Pi-deplete root and may participate in promoting root branching for resources exploration. Abbreviations: ATG: autophagy related; PHT1: PHOSPHATE TRANSPORTER 1; Pi: phosphate.