Effects of BDE3 and the Co-Existence Copper on Photosynthesis and Antioxidative Enzymes in Salvinia natans (L.)

Abstract

Due to the unregulated handling of e-waste, the co-existence of PBDEs and heavy metals in water bodies and soil has been detected with high frequency. However, the combined toxicity for aquatic creatures remains unclear. This study investigated the single and combined stress of BDE3 and copper on the photosynthesis and antioxidant enzyme system of Salvinia natans (L.). The results indicated that there were no negative effects on photosynthetic pigments under single stress of BDE3 or combined stress with copper. However, to deal with oxidative stress, antioxidant defense enzymes, including SOD and CAT, were activated in S. natans. SOD was sensitive in the first stage, while CAT activity was significantly increased until the end of 14 days of incubation. Malondialdehyde content increased significantly, which indicated that excessive reactive oxygen species from pollution of BDE3 or coexistence with copper could not be eliminated. BDE3 concentration in the aqueous phase declined with time, while copper was accumulated over time in S. natans, with BCF increasing to 0.31 ± 0.073 at the end. Our study indicated that the co-existence of copper could exacerbate the damage caused by BDE3 to S. natans in aqueous environment.