Техногенное загрязнение изменяет структуру листа и фотосинтетическую активность Calla palustris L. из природных местообитаний

Abstract

Evaluation of the leaf structural parameters and the level of CO2 assimilation changes were carried out on the emergent plant Calla palustris L. from natural habitats with different degrees of technogenic pollution (upstream and downstream of Sak-Elga river, Karabash copper smelter, Chelyabinsk region, Russia). It was found that the content of chlorophyll a significantly decreased in plants from the impact site. The rate of CO2 assimilation was also significantly low in the impact site, both per unit leaf area and per chloroplast (2 times) as well as per gram of total chlorophyll (1,6 times). Perhaps this decrease of photosynthetic rate was determined not only by the decrease in total chlorophyll concentration, but probably by the inhibition of RUBISCO in the contaminated area. No significant changes were observed in the structure of the phototrophic leaf tissues and the volume of the airenchyma. It was shown that a decrease in the sponge mesophyll cell volume in plants from the impact site was compensated by an increase in their number, whereas a decrease in the number of chloroplasts in the cell was accompanied by an increase in their volume. It is concluded that the changes in the numerical and dimensional characteristics of the mesophyll cells and chloroplasts ensure the viability of C. palustris under conditions of prolonged technogenic impact and demonstrate the plasticity of the photosynthetic apparatus.