Activity of Cell Wall-Bound and Cytosolic Peroxidases under the Aftereffect of Copper Ions in Nicotiana tabacum Plants

Abstract

The adaptation of plants to an excess of heavy metals in the environment and their recovery after elimination of the stressor is of interest in connection with the large-scale pollution of ecosystems and their remediation. This study is aimed at the aftereffect of copper ions (100 and 300 μM) in plants of Nicotiana tabacum L. The level of plant stress markers (concentration of hydrogen peroxide, activity of class III peroxidases – benzidine and guaiacol, their isoforms) during the recovery period after the removal of copper ions from the environment was evaluated in pretreatment by copper ions of different concentration and the use of control plants. During the recovery period, the concentration of hydrogen peroxide in plant organs (root, stem, and leaves) was high compared to the control. The responses of the roots and shoots under the aftereffect of the stressor were different. The activity of cytosolic guaiacol peroxidase and cell wall-bound peroxidases in root tissues increased according to the increase in Н2О2. In plants pretreated with a lower copper concentration, the activity of cell wall-bound peroxidases in the stem and cytosolic and cell wall-bound benzidine peroxidases in leaves increased. In contrast, pretreatment with a high copper concentration led to a decrease in the activity of peroxidases during the period of plant recovery. Thus, plant organs differed in the content of H2O2 and the activity of class III peroxidases localized in different compartments (apoplast and cytosol) and in their ability to recover after the removal of the stressor