Alteration of SH-group Contents in Red Beet Roots and Vacuoles under Osmotic Stress

The content of sulfhydryl groups in homogenate of red beets and isolated vacuoles under the conditions of osmotic stress was determined. It was demonstrated that the common content of sulfhydryl groups in the isolated vacuoles was 2.4 times higher, than in the homogenate. Under the conditions of osmotic stress, it was primarily denoted the reduction of common content of sulfhydryl groups in homogenate and in the isolated vacuoles. The most interesting results were obtained in determination of correlations between protein and non-protein SH-groups. Under the conditions of osmotic stress, while the contents of non-protein SH-groups in the isolated vacuoles was reduced, non-protein SH-groups in homogenate was greatly increased. This may be explained by the influx of the substances containing SH-groups out of vacuoles. Obtained results allow us to conclude that vacuoles play an important role in plant cell antioxidant processes and in maintenance of intracellular redox-homeostasis.