title: Physiological and antioxidant responses of Salvinia natans exposed to chromium-rich wastewater.
abstract: Salvinia natans possess capacity to accumulate high concentrations of chromium (Cr). Studies were carried out to evaluate physiological efficiency and defensive potential of plant exposed to Cr-rich wastewater. Among photochemical reactions, photosystem I (PS I) and photosystem II (PS II) activity noted an increase in plants exposed to Cr-rich wastewater. Fluorescence ratio F(v)/F(m) depicted no alteration in plants exposed to Cr. The activity of ribulose-1,5-biphosphate carboxylase-oxygenase (Rubisco) noted a decline, while transthylakoidal pH gradient (DeltapH) (correlative of photophosphorylation) showed increase in plants exposed to Cr-rich wastewater. Plants lacked the ability to produce malondialdehyde, but possessed efficient enzymic and non-enzymic antioxidant defense mechanisms that played important role in curtailing oxidative stress. The activities of antioxidant enzymes showed alleviation in plants exposed to Cr-rich wastewater. The levels of cellular antioxidants noted decline suggesting a defensive role in protection against oxidative stress caused by Cr. The present findings suggest that Salvinia possess efficient antioxidant machinery that curtails oxidative stress caused by Cr-rich wastewater and protects photosynthetic machinery from damage.
authors.affiliation: Department of Environmental Biology, University of Delhi, Delhi 110007, India. bhupdhir@yahoo.co.in
authors.forename: Bhupinder
authors.initials: B
authors.lastname: Dhir
authors.forename: P
authors.initials: P
authors.lastname: Sharmila
authors.forename: P
authors.initials: P
authors.lastname: Pardha Saradhi
authors.forename: Sekh Abdul
authors.initials: SA
authors.lastname: Nasim
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D002857:Chromium / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D004798:Enzymes / Q000378:metabolism; D029624:Ferns / Q000187:drug effects* / Q000201:enzymology; D007220:Industrial Waste / Q000032:analysis; D007700:Kinetics; D008315:Malondialdehyde / Q000378:metabolism; D019216:Metals, Heavy / Q000032:analysis / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D014865:Waste Disposal, Fluid; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*; D018508:Water Purification
chemical_list: D000975:Antioxidants; D004798:Enzymes; D007220:Industrial Waste; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D014867:Water; D002857:Chromium; D002734:Chlorophyll; D008315:Malondialdehyde