Plant samples and cultivationPlant s amples of P. orientale were collected from the Fenhe River wetland (37°51′N, 112°30′E), Taiyuan, Shanxi province, China (Fig. 1a). After diseased and yellowing leaves were removed, the plants were washed. The roots were soaked in 0.1% KMnO 4 for 10 minutes to kill the microorganisms. Vol. 41 no. 3 pp. 39-46 PL ISSN 2083-4772 DOI 10.1515/aep-2015 Abstract: Polygonum orientale with beautiful red fl owers can be found as one dominant species in the vicinity of most water bodies and wetlands in China. However, its phytoremediation potential has not been suffi ciently explored because little is known about its resistance to inorganic or organic pollutants. We investigated P. orientale response to low and moderate levels of phenol stress (≤ 80 mg L -1
Archives of Environmental Protection). Endpoints included phenol tolerance of P. orientale and the removal of the pollutant, antioxidant enzyme activities, damage to the cell membrane, osmotic regulators and photosynthetic pigments. In plant leaves, phenol stress signifi cantly increased the activities of peroxidase (POD) and catalase (CAT), as well as the contents of proline, soluble sugars and carotenoids, whereas superoxide dismutase (SOD), H 2 O 2 and electrolyte leakage (EL) levels remained unaltered. On the other hand, there were signifi cant decreases of soluble protein and chlorophyll contents. We demonstrated that, in combination with phenol tolerance and its removal, P. orientale has effi cient protection mechanisms against phenol-induced oxidative damage (≤ 80 mg L -1 ). We propose that P. orientale could be used as an alternative and interesting material in the phytoremediation of phenol.