Zinc oxide nanoparticles (ZnONPs) alleviate heavy metal-induced toxicity in Leucaena leucocephala seedlings: A physiochemical analysis.
The present study describes the role of zinc oxide nanoparticles (ZnONPs) in reversing oxidative stress symptoms induced by heavy metal (Cd and Pb) exposure in Leucaena leucocephala (Lam.) de Wit. Seedling growth was significantly enhanced with the augmentation of ZnONPs following Cd and Pb exposure. Heavy metal accumulations were recorded as 1253.1 mg Cd per kg DW and 1026.8 mg Pb per kg DW for the respective treatments. Results demonstrated that ZnONPs augmentation caused an increase in photosynthetic pigment and total soluble protein contents while a significant decrease in malondialdehyde (MDA-lipid peroxidation) content in leaves. Antioxidative enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were, in turn, elevated in heavy metal-exposed leaves amended with ZnONPs. The ameliorating effect of ZnO nanoparticles on oxidative stress induced toxicity was also confirmed by the reduced MDA content and the elevated level of antioxidative enzyme activities in leaf tissues of L. leucocephala seedlings. Further, addition of ZnONPs in combination with Cd and Pb metals induced distinct genomic alterations such as presence of new DNA bands and/or absence of normal bands in the RAPD pattern of the exposed plants. This study uniquely suggests a potential role of zinc oxide nanoparticles in the remediation of heavy metal contaminated media.
Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, PeriyarPalkalai Nagar, Salem, 636 011, Tamil Nadu, India. Electronic address: pvenkat67@yahoo.com.
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Venkatachalam
Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, PeriyarPalkalai Nagar, Salem, 636 011, Tamil Nadu, India.
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Jayaraj
Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, PeriyarPalkalai Nagar, Salem, 636 011, Tamil Nadu, India.
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Manikandan
Department of Biotechnology, Mother Teresa Women's University, Kodaikanal, 624 102, Tamil Nadu, India.
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Geetha
Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education, PO Box 3015, 2601 DA Delft, The Netherlands.
Eldon R
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Rene
Department of Biology, Western Kentucky University, Bowling Green, KY 42101, USA.
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NC
Sharma
Department of Biology, Western Kentucky University, Bowling Green, KY 42101, USA.
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Sahi
D000975:Antioxidants / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity; D002338:Carotenoids / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism; D007887:Fabaceae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D007854:Lead / Q000378:metabolism / Q000633:toxicity; D008315:Malondialdehyde / Q000378:metabolism; D053768:Metal Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D019216:Metals, Heavy / Q000378:metabolism / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D009195:Peroxidase / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D019105:Random Amplified Polymorphic DNA Technique; D036226:Seedlings / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D015034:Zinc Oxide / Q000737:chemistry*
D000975:Antioxidants; D018744:DNA, Plant; D019216:Metals, Heavy; D010940:Plant Proteins; D002104:Cadmium; D002734:Chlorophyll; D007854:Lead; D002338:Carotenoids; D008315:Malondialdehyde; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; D015034:Zinc Oxide
Antioxidative enzymes; Cadmium; Genetic variability; Lead; Photosynthetic pigments; Phytotoxicity