Enzymatic Analysis of Superoxide Dismutase (SOD) from Hordeum vulgare: Its Role in Drought Stress Tolerance

Superoxide dismutases (SODs) are ubiquitous metalloenzymes that constitute the first line of defense against reactive oxygen species. The role of SOD in neutralizing free radical production has already been documented. In the present investigation we have attempt to study kinetic properties of SODs in three drought sensitive and drought resistant varieties of H. vulgare. The results demonstrated that SOD displayed decreased affinities of substrate binding to their corresponding enzymes under drought conditions. The SOD isozymes profile was also analyzed and it was found that under drought conditions the only two SOD isozymes expressed as against three isozymes expressed under control. These data suggest that the decreased substrate binding affinity to SODs as well as decrease in one isozyme band of SOD under drought condition may be responsible for resistance. These findings may be used to develop drought resistance varieties of other crops.