title: Fate and effect of tire rubber ash nano-particles (RANPs) in cucumber.
abstract: There are growing interests on effects of nano-materials on living organisms including higher plants. No report is available on positive and negative effects of rubber ash nano-particles (RANPs) on edible plants. Recently, we reported the possibility of using waste tire rubber and rubber ash as zinc (Zn) fertilizer for plants. In this nutrient solution culture study, for the first time, root uptake and the effects of RANPs on growth and Zn, cadmium (Cd), and lead (Pb) concentration in cucumber was investigated. Various Zn levels (0, 1, 5, 25, 125mgL(-1)) were applied in the form of RANPs or ZnSO4. The root RANPs uptake was visualized by light (LA), scanning electron (SEM), and transmission electron microcopies (TEM). At all Zn levels, cucumber plants supplied with RANPs produced higher shoot and root biomass compared with those supplied with ZnSO4. In addition, the RANPs resulted in higher accumulation of Zn in cucumber tissues in comparison with ZnSO4; although phytotoxicity of Zn from ZnSO4 was greater than that from RANPs. Clear evidence of the RANPs penetration into the root cells was obtained by using SEM and TEM. Filaments of RANPs were also observed at the end of roots by LM and TEM. Further research is needed to clarify the fate of the RANPs in plant cells and their possible risks for food chain.
authors.affiliation: Department of Soil Science, College of Agriculture, Isfahan University of Technology, 84156-83111 Isfahan, Iran.
authors.forename: Sahar
authors.initials: S
authors.lastname: Moghaddasi
authors.affiliation: Department of Soil Science, College of Agriculture, Isfahan University of Technology, 84156-83111 Isfahan, Iran. Electronic address: amirhkhosh@cc.iut.ac.ir.
authors.forename: Amir
authors.initials: A
authors.lastname: Hossein Khoshgoftarmanesh
authors.affiliation: Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan, Iran.
authors.forename: Fatholah
authors.initials: F
authors.lastname: Karimzadeh
authors.affiliation: Beltsville, MD 20705, USA.
authors.forename: Rufus
authors.initials: R
authors.lastname: Chaney
mesh_terms: D018533:Biomass; D002104:Cadmium / Q000032:analysis; D018553:Cucumis sativus / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D007854:Lead / Q000032:analysis; D053758:Nanoparticles / Q000378:metabolism / Q000633:toxicity*; D018517:Plant Roots / Q000187:drug effects; D012408:Rubber / Q000378:metabolism / Q000633:toxicity*; D014866:Waste Products; D015032:Zinc / Q000032:analysis
chemical_list: D014866:Waste Products; D002104:Cadmium; D007854:Lead; D012408:Rubber; D015032:Zinc
keywords: Cucumber; Nano-materials; Nutrient solution culture; Tire rubber; Zinc