Review: Role of vacuoles in phosphorus storage and remobilization ($)

Phosphorus (P) is a non-renewable soil nutrient essential for plant growth. The vacuole serves as a crucial dynamic store of P that helps maintain cytosolic homeostasis. Yang et al. review vacuolar P stores, comparing P storage species and membrane proteins in yeast, algae and plants. In yeast, polyphosphate (PolyP) is a major storage form, whereas in plants the major forms are orthophosphate (PO₄^3- or Pi) in vegetative cells and inositol phosphate (InsPs) in seeds. The contributions of SYG1/PHO81/XPR1 (SPX)-domain containing proteins are highlighted, including the channel-like vacuolar P influx transporter PHT5 and its rice orthologs OsSPX-MFS1, and the putative efflux transporter OsSPX-MFS3. The contributions during P starvation of autophagy-dependent recycling other forms of organic P such as RNA are also discussed.  J. Exp. Bot. 10.1093/jxb/erw481