Effect of Hormesis in Dunaliella viridis Teodor. (Chlorophyta) Under the Influence of Copper Sulfate

摘要

Resistance of the Dunaliella viridis culture, prehminary adapted to the growth on the medium containing 20 mg/L of copper sulfate, was investigated to an increase in the concentration of copper ions up to 75 mg/L. Such a culture is shown to be stableto high concentrations of copper ions, in other words, it is able to display the effect of hormesis. The D. viridis cells resistant to copper ions (75 mg/L) may accumulate by 2000 times more copper ions as compared to the control group. In this case thecontent of carbonylated proteins (the products of free-radical processes) is twice as high in them. In the process of cultivation the Cu2+ content in cells decreased by several times. In cells displaying the hormesis effect the activity of superoxide dismutase reliably increased, while the content of free proline was twice as low. An assumption is advanced that the hormesis effect can be displayed only in the case when all cell defense systems produce joint effects. Such a behavior is characterized notonly by simple summation of all elements of defense but also by a display of emergent properties of the system.