SOS1, a Genetic Locus Essential for Salt Tolerance and Potassium Acquisition

S. J. Wu
1996 The Plant Cell  
To begin to determine which genes are essential for salt tolerance in higher plants, we identified four salt-hypersensitive mutants of Arabidopsis by using a root-bending assay on NaCI-containing agar plates. These mutants (sosl-7, sosl-2, sosl-3, and sosl-4) are allelic to each other and were caused by single recessive nuclear mutations. The SOSl gene was mapped to chromosome 2 at 29.5 f 6.1 centimorgans. The mutants showed no phenotypic changes except that their growth was >20 times more
more » ... tive to inhibition by NaCI. Salt hypersensitivity is a basic cellular trait exhibited by the mutants at all developmental stages. The sosl mutants are specifically hypersensitive to Na+ and Li+. The mutants were unable to grow on media containing low levels (below 4 mM) of potassium. Uptake experiments using B6Rb showed that sosl mutants are defective in high-affinity potassium uptake. sosl plants became deficient in potassium when treated with NaCI. The results demonstrate that potassium acquisition is a critical process for salt tolerance in glycophytic plants.
doi:10.1105/tpc.8.4.617 pmid:12239394 fatcat:z43cspndijgbfhu4oc7jhj5rza