Impact of anthropogenic toxic substances on the antioxidant defense of Ceratophyllum demersum and Egeria densa

Abstract

Considering the current increase in anthropogenic pollution of the environment, it becomes necessary to monitor the qualitative and quantitative aspects of the impact of pollution on various biological objects. Of great practical interest are the toxic effects of technogenic discharges on various hydrobionts and the basic mechanisms of their development in macrophyte plants. In this regard, this work studied the influence of heavy metal ions, anionic synthetic surfactants and their combinations on the activity of the main antioxidant enzymes in the tissues of Ceratophyllum demersum and Egeria densa. An experiment was conducted to assess changes in the freshwater macrophytes Ceratophyllum demersum and Egeria densa. The activity of antioxidant enzymes was taken into account: peroxidase, polyphenol oxidase, ascorbate oxidase and catalase. Their activity was assessed basally and in response to chemical stressors (100 µmol/l lead ions, 1% solution of anionic synthetic surfactants) individually and in combination with different exposures to toxic substances. The identified features of enzymatic activity in the tissues of aquatic macrophytes indicate different levels and power of their antioxidant protection. It has been noted that the activity of antioxidant enzymes when plants are exposed to certain types of pollutants and their combinations is determined by the chemical nature of the pollutant, the mechanism of its action on the plant organism, the duration of exposure and the localization of these enzymes in cell compartments.