The major peroxidases from root exudates of alfalfa and sorghum have different ionic status. The both peroxidases differed in the oxidation of test substrates and pollutants examined. Cationic sorghum peroxidase more effectively oxidized the parent PAHs. Anionic alfalfa peroxidase more effectively oxidized PAH-derivatives. The peroxidases of root exudates are involved in the rhizosphere degradation of pollutants.