Ferrous iron facilitates the formation of iron plaque and enhances the tolerance of Spartina alterniflora to artificial sewage stress

摘要

The ferrous iron (Fe2+) facilitates the formation of root Fe plaque of wetland plants, but its effect on the tolerance of wetland plants to artificial sewage stress has been seldom reported. In this study, the influences of Fe2+ on the formation of Fe plaque and its effects on the tolerance of Spartina alterniflora to artificial sewage stress were investigated. The artificial sewage stress decreased the plant height and chlorophyll content and significantly increased the MDA content in leaves. The symptoms of these stresses were alleviated with increasing Fe2+ concentration accompanied by significant increase in leaf alcohol dehydrogenase activity. The increase of Fe2+ concentration significantly increased the root Fe plaque content and reduced the accumulation of toxic metals in leaves of S. altennflora. These results support our hypothesis that the exogenous Fe2+ supply may enhance the stress resistance of S. alterniflora to artificial sewage containing heavy metals.