Expression of Mangrove eEF1A Enhances Tolerance to Salt and Osmotic Stress in Escherichia coli

Abstract

To analyze the mechanisms of salt tolerance in the mangrove plant, Bruguiera sexangula, functional screening for mangrove cDNAs encoding proteins essential for salt tolerance was performed using Escherichia coli as the host organism. A transformant expressing a eukaryotic elongation factor 1A homologue (Bs-eEF1A) displayed enhanced tolerance to salt and osmotic stress. This distinct function was not conferred by other plant eEF1A homologues isolated from two halophytes (Suaeda japonica and Salsola komarovii) or Arabidopsis thaliana. Levels of Bs-eEF1A transcripts in cultured B. sexangula cells were enhanced in response to salt stress. These data suggest that Bs-eEF1A plays an important role in the salt-tolerance mechanisms of B. sexangula, in addition to its original function in elongation during translation.