The Pht1;9 and Pht1;8 transporters mediate inorganic phosphate acquisition by the Arabidopsis thaliana root during phosphorus starvation
Article first published online: 11 MAY 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 195, Issue 2, pages 356–371, July 2012
How to Cite
Remy, E., Cabrito, T. R., Batista, R. A., Teixeira, M. C., Sá-Correia, I. and Duque, P. (2012), The Pht1;9 and Pht1;8 transporters mediate inorganic phosphate acquisition by the Arabidopsis thaliana root during phosphorus starvation. New Phytologist, 195: 356–371. doi: 10.1111/j.1469-8137.2012.04167.x
- Issue published online: 15 JUN 2012
- Article first published online: 11 MAY 2012
- Received: 16 January 2012, Accepted: 4 April 2012
- Arabidopsis thaliana;
- arsenate toxicity;
- phosphate starvation;
- phosphate transporter;
- plasma membrane;
- root branching;
- Saccharomyces cerevisiae
- •The activation of high-affinity root transport systems is the best-conserved strategy employed by plants to cope with low inorganic phosphate (Pi) availability, a role traditionally assigned to Pi transporters of the Pht1 family, whose respective contributions to Pi acquisition remain unclear.
- •To characterize the Arabidopsis thaliana Pht1;9 transporter, we combined heterologous functional expression in yeast with expression/subcellular localization studies and reverse genetics approaches in planta. Double Pht1;9/Pht1;8 silencing lines were also generated to gain insight into the role of the closest Pht1;9 homolog.
- •Pht1;9 encodes a functional plasma membrane-localized transporter that mediates high-affinity Pi/H+ symport activity in yeast and is highly induced in Pi-starved Arabidopsis roots. Null pht1;9 alleles exhibit exacerbated responses to prolonged Pi limitation and enhanced tolerance to arsenate exposure, whereas Pht1;9 overexpression induces the opposite phenotypes. Strikingly, Pht1;9/Pht1;8 silencing lines display more pronounced defects than the pht1;9 mutants.
- •Pi and arsenic plant content analyses confirmed a role of Pht1;9 in Pi acquisition during Pi starvation and arsenate uptake at the root–soil interface. Although not affecting plant internal Pi repartition, Pht1;9 activity influences the overall Arabidopsis Pi status. Finally, our results indicate that both the Pht1;9 and Pht1;8 transporters function in sustaining plant Pi supply on environmental Pi depletion.