Toxic effects of Cr6+ on Nymphoides peltatum mitigated by exogenous spermidine
外源亚精胺缓解荇菜(Nymphoides peltatum)Cr6+毒害的生理研究

Changes of chlorophyll content, soluble protein content, O2 generating rate and activity of protective enzymes (SOD,CAT,POD) in leaves of Nymphoides peltatum (Gmel) O.Kuntze under different concentration gradient of Cr6+ stress or exogenous spermidine treatment were studied. The results showed that:(1)under single 1mg/L Cr6+ stress, chlorophyll and soluble protein contents of the Nymphoides peltatum reached maxima, then decreased quickly; the contents of them were much higher in additionally spraying spermidine (Spd) than those in the only single Cr6+ treatment.(2)under single Cr6+ stress, the maxima of SOD,CAT and POD appeared at 2,4 and 2 mg/L Cr6+ respectively, and decreased afterward; the activities of these protective enzymes were markedly higher in spermidine treatment than those of control while the increasing and steady periods lasted longer, thereby it decreased the generation rate of active oxygen species (for example, O2). So it was concluded that spermidine could alleviate the toxic effects caused by Cr6+ stress.