Abstract:
Extensive use of antibiotics and direct discharge of their residues in hospital and industrial wastewater streams result in significant antibiotics pollution in the environment. A limited number of studies have been conducted to assess the role of organic amendments in alleviation of antibiotics’ stress on plants. The main aim of this study was to gain insight into impacts of five antibiotics (Ciprofloxacin, Levofloxacin, Ofloxacin, Amoxicillin and Ampicillin) on plants and antibiotic stress alleviation through application of different organic amendments. A pot experiment was conducted with rice (Oryza sativa L.) as model plant. Effect of five antibiotics was observed in the presence of three organic amendments (Rice husk, farmyard manure and poultry liter) upon application of antibiotics @10 mg kg-1 of soil. In pot experiment, antibiotics and organic amendments were applied to 3-week old seedlings and after four months, plants were harvested. After that physical growth parameters like root shoot length, plant biomass and nutritional composition including grain protein content, carbohydrates, phosphorous and iron were determined. At germination stage, germination rate, seedling root-shoot length, seedling biomass and vigor index were negatively impacted. Approximately, 1-2 days delay in germination was also observed. Upon exposure to antibiotics, seedling length was decreased by 71%, seedling dry biomass by 61% and vigor index by 59%. Application of organic amendments alleviated the antibiotic stress in seedling dry biomass, length and vigor index by 1.3, 3.8 and 2.1 folds, respectively as compared to the antibiotic controls. Concentration of phosphorous, iron, carbohydrates and proteins declined by 62%, 23%, 30% and 22% respectively, upon application of different antibiotics. Genotoxicity was assessed by comet assay that showed antibiotic toxicity in the following order: levofloxacin > ofloxacin> ciprofloxacin > ampicillin >amoxicillin. Poultry litter helped in alleviation of genotoxicity by 59% collectively. In general, application of amendments alleviated phytotoxicity as well as genotoxicity in the presence of different antibiotics.
