Potential of Sagittaria trifolia for Phytoremediation of Diesel

The phytoremediation potential and responses of Sagittaria trifolia to diesel were investigated. In order to elucidate the biochemical and physiological responses of S. trifolia to diesel, the chlorophyll content, root vitality, soluble protein content and antioxidant enzymes activity (peroxidase (POD), catalase (CAT) and antioxidant enzymes superoxide dismutase (SOD)) were determined in the plant tissues after 50 d of diesel treatment. The results showed the presence of S. trifolia significantly improved the removal ratios of diesel, from 21～36% in the control soils to 54～85% in the planted soils. The chlorophyll content, root vitality and soluble protein content all increased at low diesel concentration, then decreased at high diesel concentration. The activities of CAT and POD exhibited peak values at 5 g·kg^?1 diesel treatment and declined at higher diesel concentrations. However, the activity of SOD kept stable at lower diesel concentration (1 and 5 g·kg^?1), and also declined at higher diesel concentration. Collectively, S. trifolia had the ability to tolerate certain amount of diesel, but when the concentration was up to 10 g·kg^?1, the growth of S. trifolia would be restrained. The results also showed that variation of antioxidant enzyme activity was an important response in plants to diesel pollution.