ASA Southern Branch 2008 Annual Meeting
February 3-5, 2008
Dallas, TX
Monday, February 4, 2008 - 1:30 PM
Antioxidative Responses and Arsenic Localization in the Arsenic-Hyperaccumulator Chinese Brake Fern (Pteris vittata L.).
Mandakini J. Patel1, Rupali Datta1, Pravin Punamiya1, Dibyendu Sarkar1, and Shivendra Sahi2. (1) University of Texas at San Antonio, Earth and Environmental Science, One UTSA Circle, San Antonio, TX 78249, (2) Biology, Western Kentucky University, 1906 College Height Blvd # 11080, Bowling Green, KY 42101
Antioxidative responses and arsenic localization in the arsenic-hyperaccumulator Chinese brake fern (Pteris vittata L.)
Arsenic (As) is released into the environment through various anthropogenic activities such as air emissions from industries, soil amendments, pesticide applications, and chromated copper arsenic (CCA)-treated wood, which lead to elevated As levels in soils. Arsenic contamination in soils can also lead to groundwater contamination and As toxicity in plants, animals and humans. Using plant-based technology for the remediation of As from soil and water is an attractive approach. Chinese brake fern Pteris vittata was the first reported As hyperaccumulator plant, which is capable of accumulating large concentrations of As in its aboveground tissues. Under environmental stresses, plants often produce reactive oxygen species (ROS) such as superoxide, hydrogen peroxide and hydroxyl radicals, causing damage to DNA, proteins and lipids. The present study investigated the biochemical responses of Chinese brake fern to As in presence and absence of phosphorous (P). Plants were grown in quarter strength Hoagland’s media and treated with 0, 250, 500 and 750 mg/L of As in the form of sodium arsenate, and 100 mg/L of P in form of NaH2PO4 for 10 days. Induction of antioxidative enzymes catalase, peroxidase and superoxide dismutase was studied in the control and experimental plants. In addition, Hydrogen peroxide levels in fronds generated under As stress was also studied. Induction of non-enzymatic antioxidant, ascorbate was recorded. Lipid peroxidation caused to the cell membrane was studied by estimating the thiobarbutaricacid-reactive substances content. Finally, scanning electron microscopy was performed to study the localization of As in the fronds of Chinese brake fern.
Arsenic (As) is released into the environment through various anthropogenic activities such as air emissions from industries, soil amendments, pesticide applications, and chromated copper arsenic (CCA)-treated wood, which lead to elevated As levels in soils. Arsenic contamination in soils can also lead to groundwater contamination and As toxicity in plants, animals and humans. Using plant-based technology for the remediation of As from soil and water is an attractive approach. Chinese brake fern Pteris vittata was the first reported As hyperaccumulator plant, which is capable of accumulating large concentrations of As in its aboveground tissues. Under environmental stresses, plants often produce reactive oxygen species (ROS) such as superoxide, hydrogen peroxide and hydroxyl radicals, causing damage to DNA, proteins and lipids. The present study investigated the biochemical responses of Chinese brake fern to As in presence and absence of phosphorous (P). Plants were grown in quarter strength Hoagland’s media and treated with 0, 250, 500 and 750 mg/L of As in the form of sodium arsenate, and 100 mg/L of P in form of NaH2PO4 for 10 days. Induction of antioxidative enzymes catalase, peroxidase and superoxide dismutase was studied in the control and experimental plants. In addition, Hydrogen peroxide levels in fronds generated under As stress was also studied. Induction of non-enzymatic antioxidant, ascorbate was recorded. Lipid peroxidation caused to the cell membrane was studied by estimating the thiobarbutaricacid-reactive substances content. Finally, scanning electron microscopy was performed to study the localization of As in the fronds of Chinese brake fern.