Skip to main content
padlock icon - secure page this page is secure

Free Content Over-expression of PHO1 in Arabidopsis leaves reveals its role in mediating phosphate efflux

Download Article:
 Download
(PDF)
 
Summary

Inorganic phosphate (Pi) homeostasis in multi-cellular eukaryotes depends not only on Pi influx into cells, but also on Pi efflux. Examples in plants for which Pi efflux is crucial are transfer of Pi into the xylem of roots and release of Pi at the peri-arbuscular interface of mycorrhizal roots. Despite its importance, no protein has been identified that specifically mediates phosphate efflux either in animals or plants. The Arabidopsis thaliana PHO1 gene is expressed in roots, and was previously shown to be involved in long-distance transfer of Pi from the root to the shoot. Here we show that PHO1 over-expression in the shoot of A. thaliana led to a two- to threefold increase in shoot Pi content and a severe reduction in shoot growth. 31P-NMR in vivo showed a normal initial distribution of intracellular Pi between the cytoplasm and the vacuole in leaves over-expressing PHO1, followed by a large efflux of Pi into the infiltration medium, leading to a rapid reduction of the vacuolar Pi pool. Furthermore, the Pi concentration in leaf xylem exudates from intact plants was more than 100-fold higher in PHO1 over-expressing plants compared to wild-type. Together, these results show that PHO1 over-expression in leaves leads to a dramatic efflux of Pi out of cells and into the xylem vessel, revealing a crucial role for PHO1 in Pi efflux.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: Arabidopsis; NMR; PHO1; efflux; phosphate; xylem

Document Type: Research Article

Affiliations: 1: Département de Biologie Moléculaire Végétale, Biophore, Université de Lausanne, CH-1015 Lausanne, Switzerland 2: Laboratoire de Physiologie Cellulaire Végétale, Centre d’Energie Atomique, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France 3: Laboratoire de géologie de l’ingénieur et de l’environnement, Bâtiment GC, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland

Publication date: May 1, 2011

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more