title: Single-bilayer graphene oxide sheet impacts and underlying potential mechanism assessment in germinating faba bean (Vicia faba L.).
abstract: This study investigates the impact of different single-bilayer graphene oxide sheet (hereafter 'graphene oxide', GO; size: 0.5-5 μm) concentrations (0, 100, 200, 400, 800 and 1,600 mg L(-1)) and underlying potential mechanisms in germinating faba bean (Vicia faba L.) seedlings. The study revealed both positive and negative concentration-dependent GO-effects on V. faba. Significant negative impacts of GO concentrations (ordered by magnitude of effect: 1600>200>100 mg GO L(-1)) were indicated by decreases in growth parameters and the activity of H2O2-decomposing enzymes (ascorbate peroxidase, APX; catalase, CAT), and by increases in the levels of electrolyte leakage (EL), H2O2, and lipid and protein oxidation. The positive impacts of 400 and 800 mg GO L(-1) included significant improvements in V. faba health status indicated by decreased levels of EL, H2O2, and lipid and protein oxidation, and by enhanced H2O2-decomposing APX and CAT activity, and increased proline and seed-relative water content. V. faba seedlings-polypeptide patterns strongly substantiated these GO-concentration effects. Overall, the positive effects of these two GO concentrations (800>400 mg L(-1)) on V. faba seedlings indicate their safe nature and allow to suggest further studies.
authors.affiliation: Department of Chemistry and Centre for Environmental & Marine Studies (CESAM), University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Naser A
authors.initials: NA
authors.lastname: Anjum
authors.affiliation: Department of Mechanical Engineering and Centre for Mechanical Technology & Automation (TEMA), University of Aveiro, Aveiro 3810-193, Portugal.
authors.forename: Neetu
authors.initials: N
authors.lastname: Singh
authors.affiliation: Department of Mechanical Engineering and Centre for Mechanical Technology & Automation (TEMA), University of Aveiro, Aveiro 3810-193, Portugal.
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Singh
authors.affiliation: Department of Emergency Medicine, Brain Research Laboratory, 1365B Clifton Road NE, Suite 5100, Emory University, Atlanta, GA 30322, USA.
authors.forename: Iqbal
authors.initials: I
authors.lastname: Sayeed
authors.affiliation: Department of Chemistry and Centre for Environmental & Marine Studies (CESAM), University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Armando C
authors.initials: AC
authors.lastname: Duarte
authors.affiliation: Department of Chemistry and Centre for Environmental & Marine Studies (CESAM), University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Eduarda
authors.initials: E
authors.lastname: Pereira
authors.affiliation: Department of Chemistry and Centre for Environmental & Marine Studies (CESAM), University of Aveiro, 3810-193 Aveiro, Portugal; Department of Biology and Centre for Environmental & Marine Studies (CESAM), University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: ahmadr@ua.pt.
authors.forename: Iqbal
authors.initials: I
authors.lastname: Ahmad
mesh_terms: D002374:Catalase / Q000378:metabolism; D018525:Germination / Q000187:drug effects*; D006108:Graphite / Q000633:toxicity*; D006861:Hydrogen Peroxide / Q000378:metabolism; D010084:Oxidation-Reduction; D036226:Seedlings / Q000187:drug effects / Q000502:physiology; D012989:Soil Pollutants / Q000633:toxicity*; D031307:Vicia faba / Q000187:drug effects* / Q000502:physiology
chemical_list: D012989:Soil Pollutants; D006108:Graphite; D006861:Hydrogen Peroxide; D002374:Catalase
keywords: Graphene oxide; Oxidative stress; Phytotoxicity; Polypeptide pattern; Vicia faba