Conservation of the Salt Overly Sensitive Pathway in Rice

The salt tolerance of rice (Oryza sativa) correlates with the ability to exclude Na+ from the shoot and to maintain a low cellular Na+/K+ ratio. We have identified a rice plasma membrane Na+/H+ exchanger that, on the basis of genetic and biochemical criteria, is the functional homolog of the Arabidopsis (Arabidopsis thaliana) salt overly sensitive 1 (SOS1) protein. The rice transporter, denoted by OsSOS1, demonstrated a capacity for Na+/H+ exchange in plasma membrane vesicles of yeast (Saccharomyces cerevisiae) cells and reduced their net cellular Na+ content. The Arabidopsis protein kinase complex SOS2/SOS3, which positively controls the activity of AtSOS1, phosphorylated OsSOS1 and stimulated its activity in…

• MO
  Ministry of Agriculture, Forestry and Fisheries