title: Physiological and antioxidant response of wheat (Triticum aestivum) seedlings to fluoroquinolone antibiotics.
abstract: Combinations of antibiotics occur in terrestrial environments due to excessive prescription, consumption, and disposal and have adverse effects, including crop toxicity. We examined short-term (20-d) toxicity of the fluoroquinolone antibiotics ciprofloxacin, enrofloxacin, levofloxacin, and their mixture in a germination and a greenhouse sand culture study with wheat. We tested the hypothesis that oxidative stress plays a role in toxicity by examining stress products and antioxidants involved in detoxifying reactive oxygen species (ROS) during stress. Germination was unaffected by any antibiotic concentration or mixture used. The highest antibiotic concentrations, 100 and 300 mg L-1, significantly decreased wheat growth. In 20 days exposure the maximum malondialdehyde production (2.45 μmol g-1fresh weight), total phenols (16.40 mg g-1of extract), and total antioxidant capacity (17.74 mg of Vitamin C g-1of extract) and maximum activities of superoxide dismutase (7.99 units mg-1protein min-1) and ascorbate peroxidase (0.69 μmol ascorbate mg-1protein min-1) significantly increased compared to the control. In contrast, catalase (0.45 mmol H2O2mg-1protein min-1) and peroxidase (0.0005 units mg-1protein min-1) activity significantly decreased compared to the control. We conclude that high antibiotic concentrations in the plant growth medium reduced wheat growth by causing oxidative stress. The capacity to respond to oxidative stress was compromised by increasingly higher antibiotic concentrations in some enzyme systems. This stress damaged the physiological structure of the young plants and could reduce crop productivity in the long term. Consequently, fluoroquinolone-contaminated water challenges developing countries with constraints on available water for irrigation.
authors.affiliation: Department of Environmental Sciences, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi 46000, Pakistan.
authors.forename: Luqman
authors.initials: L
authors.lastname: Riaz
authors.affiliation: Department of Environmental Sciences, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi 46000, Pakistan.
authors.forename: Tariq
authors.initials: T
authors.lastname: Mahmood
authors.affiliation: Department of Plant & Soil Sciences University of Kentucky, Lexington, KY 40546-0091, USA. Electronic address: mark.coyne@uky.edu.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Coyne
authors.affiliation: Department of Environmental Sciences, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi 46000, Pakistan.
authors.forename: Azeem
authors.initials: A
authors.lastname: Khalid
authors.affiliation: Department of Environmental Sciences, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi 46000, Pakistan.
authors.forename: Audil
authors.initials: A
authors.lastname: Rashid
authors.affiliation: Department of Environmental Sciences, COMSATS Institute of Information and Technology, Abbotabad 22010, Pakistan.
authors.forename: Malik Tahir
authors.initials: MT
authors.lastname: Hayat
authors.affiliation: Department of Entomology, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi 46000, Pakistan.
authors.forename: Asim
authors.initials: A
authors.lastname: Gulzar
authors.affiliation: Department of Environmental Sciences, COMSATS Institute of Information Technology, Vehari 61100, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Amjad
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D000077422:Enrofloxacin; D024841:Fluoroquinolones / Q000032:analysis / Q000494:pharmacology*; D018525:Germination / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D009195:Peroxidase / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects* / Q000254:growth & development*; D013482:Superoxide Dismutase / Q000378:metabolism; D014908:Triticum / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D024841:Fluoroquinolones; D017382:Reactive Oxygen Species; D000077422:Enrofloxacin; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; D001205:Ascorbic Acid
keywords: Ciprofloxacin; Enrofloxacin; Levofloxacin; Pharmaceuticals; Phytotoxicity