Copper-induced toxicity in aquatic macrophyte, Hydrilla verticillata: effect of pH

Abstract

: Copper uptake and toxicity were evaluated in Hydrilla verticillata. Its effect on lipid peroxidation, chlorophyll, protein, ascorbate, cysteine and sugars was studied at pH 6.8. Dose- and durationdependent uptake of Cu followed by a significant decrease in malondialdehyde and sugar content was found in plant tissue. Chlorophyll, ascorbic acid and protein contents were increased non-significantly up to 8, 16 and 32 þM Cu, respectively. Cysteine content was slightly increased at lower concentrations followed by a significant decline. At 80 þM Cu, plants of H. verticillata showed significant toxic effects after 168 h of exposure indicating the sensitivity of the plant to this level of Cu stress. The effect of low and high pH in combination with different concentrations of Cu was determined at 168 h of exposure. Low pH (4.5) enhanced Cu toxicity while at high pH (9.5) toxicity was considerably reduced.

Copper-induced oxidative stress in Alternanthera philoxeroides callus

“…4). This was attributed to the decline of total PUFA, which was prone to peroxidative damage (Jones et al 1987;Gupta et al 1996). Similar results had been found in Cd-treated hydrophytes (Hydrilla, Wolffia, and Ceratophyllum) (Dhir et al 2004), Cu-treated Hydrilla verticillata , and Hg-treated Bacopa monnieri .…”

Oxidative Stress Induced by Iron inHydrilla verticillata(l.f.) Royle: Response ofAntioxidants

“…The accumulation of heavy metals by submerged macrophytes has been reported in several plants (Guilizzoni, 1991;Sinha et al, 1994b;Gupta et al, 1996). However, the active uptake was significantly low compared to total accumulation.…”

“…Chlorophyll content was not affected up to 96 h which may be due to high requirement of Fe for chlorophyll biosynthesis. Increase in the chlorophyll content on treatment with Cu has been reported at lower concentrations (Gupta et al, 1996) in the plants of H. verticillata. In the present study, chlorophyll content decreased at higher concentrations which conforms with the findings of these authors.…”

Estudo dos mecanismos de detoxificação e tolerância aos metais cromo e cobre em Pseudokirchneriella subcapitata e Pistia stratiotes e o uso das macrófitas Typha sp e Phragmites sp na remoção de nutrientes em wetlands construídos

“…In this model, only time quadratic was significant in leaves (Table 3) PRASAD, 1998) and P. stratiotes (SINHA et al, 2005). On the other hand, they are in disagreement with the studies realized by Gupta et al (1996) that demonstrate decrease in MDA content in copper stressed H. verticillata plants as compared to control plants.…”