Body of Abstract: Soil salinity is one of the major threats to agricultural productivity worldwide. Salt stress exposure alters root and shoot growth rates, thereby affecting overall plant productivity and fitness. It remains elusive how alteration in root-to-shoot ratio under salt stress contributes to the overall plant salt stress response. Through a Genome-Wide Association Study, we identified domain-of-unknown-function (DUF247) as the putative locus underlying the maintenance of the root-to-shoot ratio under salt stress conditions. Characterization of DUF247 revealed that the full-length protein resides in the plasma membrane, and the removal of the C-terminal transmembrane domain results in nuclear and cytosolic localization. DUF247 promoter was active in the root stele and induced by salt stress during early vegetative development. Loss-of-function mutants showed decreased sodium accumulation, increased shoot growth rate, and enhanced root suberization under salt stress, suggesting that DUF247 acts as a negative regulator of salt tolerance. Further elucidation of the molecular mechanisms in which DUF247 acts is ongoing using Y2H and transcriptomics studies. Evaluating the molecular context of DUF247 will reveal new mechanisms of salt tolerance, which can be adapted as a potential target in crop plants.