• Please log in or register to access this feature.

SEARCH

SEARCH BY CITATION

Keywords:

  • homeostasis;
  • miRNA;
  • OsPHR2;
  • phosphate;
  • rice;
  • SPX;
  • transporter

Summary

  • Proteins possessing the SPX domain are found in several proteins involved in inorganic phosphate (Pi) transport and signalling in yeast and plants. Although the functions of several SPX-domain protein subfamilies have recently been uncovered, the role of the SPX-MFS subfamily is still unclear.
  • Using quantitative RT-PCR analysis, we studied the regulation of SPX-MFS gene expression by the central regulator, OsPHR2 and Pi starvation. The function of OsSPX-MFS1 in Pi homeostasis was analysed using an OsSPX-MFS1 mutant (mfs1) and osa-miR827 overexpression line (miR827-Oe). Finally, heterologous complementation of a yeast mutant impaired in Pi transporter was used to assess the capacity of OsSPX-MFS1 to transport Pi.
  • Transcript analyses revealed that members of the SPX-MFS family were mainly expressed in the shoots, with OsSPX-MFS1 and OsSPX-MFS3 being suppressed by Pi deficiency, while OsSPX-MFS2 was induced. Mutation in OsSPX-MFS1 (mfs1) and overexpression of the upstream miR827 (miR827-Oe) plants impaired Pi homeostasis in the leaves. In addition, studies in yeast revealed that OsSPX-MFS1 may be involved in Pi transport.
  • The results suggest that OsSPX-MFS1 is a key player in maintaining Pi homeostasis in the leaves, potentially acting as a Pi transporter.