Physiological Responses of Four Submerged Macrophytes to Phenanthrene Exposure
Phenanthrene is a typical polycyclic aromatic hydrocarbon (PAH) found in contaminated water. This study investigated physiological responses of four submerged macrophytes to phenanthrene stress with time, following 40-day exposure to two concentrations of phenanthrene solutions in an outdoor-simulated experiment. A number of parameters including malondialdehyde, soluble carbohydrate and soluble protein contents were monitored. Results showed that the concentrations of phenanthrene in solution decreased obviously with duration of exposure. Subsequently, these four submerged macrophytes could recovered, although several days of phenanthrene exposure resulted in some adverse effects on these plants such as increased malondialdehyde and water soluble protein contents as well as reduced water soluble carbohydrate contents. Changes of these physiological parameters in these submerged macrophytes reflected their continuous tolerance to phenanthrene.