title: Does seed size and surface anatomy play role in combating phytotoxicity of nanoparticles?
abstract: Rapid utilization of nano-based products will inevitably release nanoparticles into the environment with unidentified consequences. Plants, being an integral part of ecosystem play a vital role in the incorporation of nanoparticles in food chain and thus, need to be critically assessed. The present study assesses the comparative phytotoxicity of nanoparticle, bulk and ionic forms of zinc at different concentrations on selected plant species with varying seed size and surface anatomy. ZnO nanoparticles were chosen in view of their wide spread use in cosmetics and health care products, which allow their direct release in the environment. The impact on germination rate, shoot & root length and vigour index were evaluated. A concentration dependent inhibition of seed germination as well as seedling length was observed in all the tested plants. Due to the presence of thick cuticle on testa and root, pearl millet (xerophytic plant) was found to be relatively less sensitive to ZnO nanoparticles as compared to wheat and tomato (mesophytic plants) with normal cuticle layer. No correlation was observed between nanoparticles toxicity and seed size. The results indicated that variations in surface anatomy of seeds play a crucial role in determining the phytotoxicity of nanoparticles. The present findings significantly contribute to assess potential consequences of nanoparticle release in environment particularly with major emphasis on plant systems. It is the first report which suggests that variations observed in phytotoxicity of nanoparticles is mainly due to the predominant differences in size and surface anatomy of tested plant seeds and root architecture. Effect of various concentrations of nano ZnO, bulk ZnO and zinc sulphate on the growth of pearl millet (A), tomato (B) and wheat (C) seedlings.
authors.affiliation: Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, 333031, India.
authors.forename: Navin
authors.initials: N
authors.lastname: Jain
authors.affiliation: Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, 333031, India.
authors.forename: Arpit
authors.initials: A
authors.lastname: Bhargava
authors.affiliation: Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, 333031, India.
authors.forename: Vikram
authors.initials: V
authors.lastname: Pareek
authors.affiliation: Department of Botany, Gandhi Faiz-E-Aam College, Shahjahanpur, 242001, India.
authors.forename: Mohd
authors.initials: M
authors.lastname: Sayeed Akhtar
authors.affiliation: Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, 333031, India. jpanwar@pilani.bits-pilani.ac.in.
authors.forename: Jitendra
authors.identifier: http://orcid.org/0000-0002-0750-9745
authors.initials: J
authors.lastname: Panwar
mesh_terms: D018551:Solanum lycopersicum / Q000033:anatomy & histology* / Q000187:drug effects; D053768:Metal Nanoparticles / Q000633:toxicity*; D031782:Pennisetum / Q000033:anatomy & histology* / Q000187:drug effects; D018517:Plant Roots / Q000033:anatomy & histology / Q000187:drug effects; D012639:Seeds / Q000033:anatomy & histology / Q000187:drug effects; D014908:Triticum / Q000033:anatomy & histology* / Q000187:drug effects; D015034:Zinc Oxide / Q000633:toxicity*
chemical_list: D015034:Zinc Oxide
keywords: Nano ZnO; Nanoparticle pollution; Phytotoxicity; Seed germination