Elongation factor 1 alpha from A. thaliana functions as molecular chaperone and confers resistance to salt stress in yeast and plants

Salt stress is a major environmental factor influencing plant growth and development and plants have many tolerance mechanisms to overcome salt stress. To identify salt tolerance determinants in higher plants, an Arabidopsis cDNA clone that encodes translation elongation factor 1 alpha (AtEF1 alpha) was isolated by functional complementation of the salt-sensitive phenotype of a calcineurin (CaN)-deficient yeast mutant(cnb Delta). AtEF1 alpha displayed a chaperone activity in a dose-dependant manner in vitro and the chaperone activity of AtEF1 alpha was required for NaCl tolerance in cnb Delta cells. When compared with wildtype Arabidopsis, AtEF1 alpha knock-out plants were more sensitive to NaCl stress. Furthermore, transgenic plants with transgene AtEF1 alpha were more tolerant to NaCl than the wild-type. These results suggest that AtEF1 alpha functions as molecular chaperone, and this activity enhances NaCl tolerance in yeast and plants. (C) 2009 Elsevier Ireland Ltd. All rights reserved.