Activity of phase I and phase II detoxication enzymes in different cormus parts of Phragmites australis

Enzymes of phase I and phase II of the xenobiotic detoxication pathway (eth oxyresorufin-O-deethylase, peroxidases, microsomal and soluble glutathione- S-transferases) were measured in roots, stems, and leaves of Phragmites aus tralis, revealing different enzyme activities in these parts. Highest enzym e activities were measured in the root followed by the leaf. Enzyme activit ies detected in the stem were low compared with those in the root and leaf. The high detoxication capacity of the root and the leaf might be due to ve ry high exposure to xenobiotics and to the high levels of metabolism in the se cormus parts. The function of the stem of Phragmites is mainly transport ation, so a high detoxication level is not useful, as indicated by the low enzyme activities. (C) 1999 Academic Press.