| Late embryogenesis abundant (LEA) proteins are ubiquitous in plants and accumulate during the later stages of seed maturation and in vegetative tissues following dehydration, osmotic, salinity, and low-temperature stress or ABA application. Many LEA proteins also belong to a group of proteins called 'hydrophilins' due to their high hydrophilicity and glycine residue content, high degree of evolutionary conservation, and expression in response to water-deficit stress. Certain classes of LEA proteins have been demonstrated to improve cold, osmotic, salinity, and water deficit tolerance in yeast and plants, however, the exact function of most LEA proteins remains unclear.; To test the functional role of group 1 and group 2 LEA proteins from soybean in stress adaptation, we constitutively expressed the soybean group 1 LEA protein, GmD-19, and the soybean group 2 LEA protein, GmDHN1, respectively, in transgenic Arabidopsis thaliana . Results suggest that group 1 and group 2 LEA proteins can confer protection against salinity, and water-deficit stress and group 2 LEA proteins can confer resistance to freezing stress. Possible mechanisms for the observed improvements in abiotic stress resistance are discussed. (Abstract shortened by UMI.)... |
