Accumulation of heavy metals in leaves of submerged hydrophytes (Elodea canadensis Michx. and Potamogeton perfoliatus L.) and their responses to the effect of the wastewater of a metallurgical plant

The accumulation of heavy metals (Cu, Ni, Zn, Mn, and Fe), parameters of the photosynthetic apparatus, and flavonoid content in leaves of two widespread species of submerged hydrophytes ( Elodea canadensis Michx. and Potamogeton perfoliatus L.) from habitats with different levels of pollutions have been studied. The investigations are carried out in the surroundings of the metallurgical plant in the town of Revda, Sverdlovsk oblast, Russia (Revda River, upstream and downstream the confluence of the sewage). It is shown that hydrophytes from polluted habitats (impact site) differ from the plants of a less polluted zone (background site) by a higher accumulation of heavy metals (HMs), greater leaf thickness, and larger cells and chloroplasts. Plants from the polluted site are characterized by a high content of photosynthetic pigments, while flavonoid content in the leaves is lower. The identified trends indicate a high adaptive potential of these species of plants and their ability to inhabit in an aquatic environment polluted with metals and other pollutants.