The interactive effects of mercury and selenium on metabolic profiles, gene expression and antioxidant enzymes in halophyteSuaeda salsa

Abstract

Suaeda salsa is the pioneer halophyte in the Yellow River Delta and was consumed as a popular vegetable. Mercury has become a highly risky contaminant in the sediment of intertidal zones of the Yellow River Delta. In this work, we investigated the interactive effects of mercury and selenium in S. salsa on the basis of metabolic profiling, antioxidant enzyme activities and gene expression quantification. Our results showed that mercury exposure (20 μg L(-1)) inhibited plant growth of S. salsa and induced significant metabolic responses and altered expression levels of INPS, CMO, and MDH in S. salsa samples, together with the increased activities of antioxidant enzymes including SOD and POD. Overall, these results indicated osmotic and oxidative stresses, disturbed protein degradation and energy metabolism change in S. salsa after mercury exposures. Additionally, the addition of selenium could induce both antagonistic and synergistic effects including alleviating protein degradation and aggravating osmotic stress caused by mercury.

The antioxidant system in Suaeda salsa under salt stress

“…54 The regulation of antioxidant system in S. salsa under some other stresses Liu and collaborators found that mercury exposure inhibited plant growth of S. salsa and induced significant metabolic responses and increased activities of antioxidant enzymes including SOD and POD. 58 And after exposure to environmentally relevant lead and zinc for 15 days, the expression levels of CAT genes were significantly upregulated in S. salsa. 59 Under chilling stress, the SOD and APX activity in S. salsa increased first and then declined, while the production of ROS (O 2• − and H 2 O 2 ) decreased first and then increased.…”