Biochemical Adaptation of Barley Root Cells to Toxic Substances. II. Effect of Heavy Metals on Phosphohydrolase Activity

We studied the effect of heavy metals such as Cu, Zn, Cd, and Pb on the activity of membrane-bound and soluble phosphohydrolases of barley root cell apoplast. The effect of heavy metals on the activity of acid phosphatase and acid nucleotidases proved to depend on the presence of calcium and magnesium ions in the incubation buffer, the condition and form of the enzymes, as well as the dose and moment of the addition of heavy metals. We propose changing the activity of acid phosphohydrolases in barley root cell apoplast as a possible mechanism of barley adaptation to the toxic effect of heavy metals.