US EPA

1070322 

Journal Article 

The Pht1;9 and Pht1;8 transporters mediate inorganic phosphate acquisition by the Arabidopsis thaliana root during phosphorus starvation 

Remy, E; Cabrito, TR; Batista, RA; Teixeira, MC; Sá-Correia, I; Duque, P 

2012 

1 

New Phytologist
ISSN: 0028-646X
EISSN: 1469-8137 

195 

2 

356-371 

English 

22578268 

10.1111/j.1469-8137.2012.04167.x 

WOS:000305472100010 

http://doi.wiley.com/10.1111/j.1469-8137.2012.04167.x
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• 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. 

Arabidopsis thaliana; arsenate toxicity; phosphate starvation; phosphate transporter; plasma membrane; root branching; Saccharomyces cerevisiae