Physiological responses of submerged macrophytes to dibutyl phthalate (dbp) exposure

Abstract

Physiological and biochemical perturbations of some submerged macrophytes, including Ceratophyllum demersum, Vallisneria spiralis and Potamogeton maackianus, were investigated following 25-day exposures to different concentrations of dibutyl phthalate. Plants were assayed for malon-diadehyde, soluble carbohydrate, chlorophyll, protein and glutathione. Results showed that contents of malon-diadehyde in submerged macrophytes decreased irregularly with increase in dibutyl phthalate. Contents of soluble carbohydrate in the Vallisneria spiralis had negative correlations with the concentrations of dibutyl phthalate and contents of soluble carbohydrate in the Potamogeton maackianus had positive correlation with increase in dibutyl phthalate. The contents of chlorophyll in Vallisneria spiralis changed irregularly and those of Ceratophyllum demersum and Potamogeton maackianus were higher than the control. The contents of protein and glutathione in these submerged macrophytes were less than the control. Contents of glutathione in Vallisneria spiralis had significantly negative correlations with increasing concentrations of dibutyl phthalate. Content of protein and glutathione might be considered as sensitive indexes of early damage to submerged macrophytes by dibutyl phthalate.