Bioaccumulation and physiological effects of mercury in Pteris vittata and Nephrolepis exaltata

Abstract

Anatomical, histochemical and biochemical approaches were used to study mercury uptake and phytotoxicity as well as anti-oxidative responses in two species of ferns [Chinese brake fern (Pteris vittata) and Boston fern (Nephrolepis exaltata)], grown in a hydroponic system. The roots of both cultivars accumulated large amounts of mercury, but exhibited limited mercury translocation to shoots. Mercury exposure led to more pronounced phytotoxicity accompanied by stronger oxidative stress in the shoots of P. vittata than in N. exaltata. N. exaltata established a more effective anti-oxidative system against mercury-induced oxidative stress than did P. vittata. The activity of anti-oxidative enzymes (superoxide dismutase, catalase and glutathione reductase) increased. The reduced ascorbate (ASA) and oxidized ascorbate (DHA) are regulated. Mercury exposure led to an increase in the concentration of glutathione (GSH) in both fern species. The present study suggests that N. exaltata is more tolerant to mercury exposure than P. vittata, which has been also reported to be more tolerant to arsenic exposure. N. exaltata may thus have potential for phytostabilization of soils or phytofiltration of waste water contaminated with mercury.

Decontamination of Lead from aquatic environment by exploitation of floating macrophyte Azolla microphylla Kauf

“…Growth inhibitory rate % (GIR) was calculated according to Wilkins (1978) [23] . The relative water content (RWC) was also calculated as described by Chen et al (2009) [24] . RWC (%) = [(FW-DW)/ FW] x100, where FW-fresh weight & DW-dry weight.…”

Copper microlocalisation, ultrastructural alterations and antioxidant responses in the nodules of white lupin and soybean plants grown under conditions of copper excess

“…The 3 mL reaction mixture contained 40 mM phosphate buffer (pH 7.8), 13 mM methionine, 75 M NBT, 2 M riboflavin, 0. (Chen et al, 2009). …”

Expression Analysis of WRKY Transcription Factor Genes in Response to Abiotic Stresses in Horsegram (<i>Macrotyloma uniflorum</i> (Lam.) Verdc.)

“…MDA, the product of lipid peroxidation is often used as an indicator to check the extent of oxidative stress in plant [23]. The formation of ROS increases the levels of cellular lipid peroxidation, such increase in the production of ROS and peroxidation levels differ from species and severity of stress [24].…”