Copper contaminated water mediated biochemical changes on charophyte species Chara braunii

Abstract

Abstract Over the past few decades water bodies have been heavily contaminated by the heavy metals thus charophytes communities tended to disappear from their own habitat niches. In this experiment we hypothesized that elevating Cu concentrations and increasing exposure time deviates the biochemical responses of Chara braunii. For evaluating this hypothesis we considered changes in plant reactive oxygen species (ROS) mainly as hydrogen peroxide. Thereafter, scavenging antioxidant activities were measured (POD, CAT) while pigment content assessed means of Chl a, Chl b and Carotenoids. Each treatment contains 3 replicates and subjected to four levels of Cu concentrations (0ppm, 1ppm, 5ppm, and 10ppm) for over four days respectively. Compared to the control, all dosages of Cu concentrations and exposure times were caused to trigger H2O2 generation. Observed results revealed that dramatic increases of H2O2 level on the 1st day of copper contamination by the 10ppm concentration. Conversely, after 1st day H2O2 content continuously tended to decreases and in 4th day it shown the lowest value. Moreover, C. braunii exhibited significant increase in the catalase activity and peroxidase activity for detoxifying Cu toxicity for short duration whereas inhibited antioxidant activity on prolonged exposure. Consequently, chlorophyll pigments content impaired significantly and deteriorated plant color suggests subjected plant were under extreme stress. This study results indicated that exposure to Cu contaminated water is lethal for charophyte growth and the physiological process by enhancing oxidative damages to the cells.