HISTONE DEACETYLASE ACTIVITY AND REACTIVE OXYGEN SPECIES CONTENT IN THE TISSUE CULTURE OF Arabidopsis thaliana UNDER NORMAL CONDITIONS AND DEVELOPMENT OF ACUTE OSMOTIC STRESS.

The possible involvement of histone deacetylase (HDAC) in regulation of ROS content in the tissue culture of Arabidopsis thaliana under normal conditions and under development of acute osmotic stress was studied by using inhibition assay with application of trichostatin A (TSA). It was found that in the tissue culture grown under normal conditions a decrease in HDAC activity by means of TSA led to increase of the ROS content. Similar but more pronounced alterations occurred under stress. At the same time an increase in histone acetyltransferase (HAT) activity was also observed. The possible mechanisms of HDAC and HAT participation in regulation of ROS content by changes in expression of genes that are responsible for ROS production and antioxidant activity are discussed.