title: Role of vacuoles in phosphorus storage and remobilization.
abstract: Vacuoles play a fundamental role in storage and remobilization of various nutrients, including phosphorus (P), an essential element for cell growth and development. Cells acquire P primarily in the form of inorganic orthophosphate (Pi). However, the form of P stored in vacuoles varies by organism and tissue. Algae and yeast store polyphosphates (polyPs), whereas plants store Pi and inositol phosphates (InsPs) in vegetative tissues and seeds, respectively. In this review, we summarize how vacuolar P molecules are stored and reallocated and how these processes are regulated and co-ordinated. The roles of SYG1/PHO81/XPR1 (SPX)-domain-containing membrane proteins in allocating vacuolar P are outlined. We also highlight the importance of vacuolar P in buffering the cytoplasmic Pi concentration to maintain cellular homeostasis when the external P supply fluctuates, and present additional roles for vacuolar polyP and InsP besides being a P reserve. Furthermore, we discuss the possibility of alternative pathways to recycle Pi from other P metabolites in vacuoles. Finally, future perspectives for researching this topic and its potential application in agriculture are proposed.
authors.affiliation: Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Shu-Yi
authors.initials: SY
authors.lastname: Yang
authors.affiliation: Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Teng-Kuei
authors.initials: TK
authors.lastname: Huang
authors.affiliation: Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Kuo
authors.affiliation: Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Tzyy-Jen
authors.initials: TJ
authors.lastname: Chiou
mesh_terms: D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism*; D015003:Yeasts / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D010940:Plant Proteins; D010758:Phosphorus
keywords: Autophagy; SPX domain; inositol phosphate; orthophosphate; phosphate transporter; phosphorus; polyphosphate; vacuole