SiO2 nanomaterial as a tool to improve Hordeum vulgare L. tolerance to nano-NiO stress

Cristiano Soares; Simão Branco-Neves; Alexandra de Sousa; Manuel Azenha; Ana Cunha; Ruth Pereira; Fernanda Fidalgo

doi:10.1016/j.scitotenv.2017.12.002

SiO₂ nanomaterial as a tool to improve Hordeum vulgare L. tolerance to nano-NiO stress

Sci Total Environ. 2018 May 1:622-623:517-525. doi: 10.1016/j.scitotenv.2017.12.002. Epub 2017 Dec 13.

Authors

Cristiano Soares¹, Simão Branco-Neves², Alexandra de Sousa², Manuel Azenha³, Ana Cunha⁴, Ruth Pereira⁵, Fernanda Fidalgo²

Affiliations

¹ BioISI - Biosystems & Integrative Sciences Institute, Biology Department, Faculty of Sciences, University of Porto, Rua Campo Alegre s/n, 4169-007 Porto, Portugal. Electronic address: up201003798@fc.up.pt.
² BioISI - Biosystems & Integrative Sciences Institute, Biology Department, Faculty of Sciences, University of Porto, Rua Campo Alegre s/n, 4169-007 Porto, Portugal.
³ CIQ-UP, Chemistry and Biochemistry Department, Faculty of Sciences, University of Porto, Rua Campo Alegre s/n, 4169-007 Porto, Portugal.
⁴ Biology Department & CITAB - Centre for the Research and Technology of Agro-Environmental and Biological Sciences, School of Sciences, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
⁵ CIIMAR, Interdisciplinary Centre of Marine & Environmental Research, Rua dos Bragas, n. 289, 4050-123 Porto, Portugal; Biology Department, Green-UP/CITAB-UP, Faculty of Sciences of the University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal.

PMID: 29220775
DOI: 10.1016/j.scitotenv.2017.12.002

Abstract

This work was designed to assess the potential role of silicon dioxide nanomaterial (nano-SiO₂) in enhancing barley's tolerance to nickel oxide nanomaterial (nano-NiO). For this purpose, plants were grown for 14days under nano-NiO (120mgkg^-1) single and co-exposure with nano-SiO₂ (3mgkg^-1). The exposure of barley to nano-NiO caused a significant decrease in growth-related parameters and induced a negative response on the photosynthetic apparatus. However, upon nano-SiO₂ co-exposure, the inhibitory effects of nano-NiO were partially reduced, with lower reductions in fresh and dry biomass, and with the recovery of the photosynthesis-related parameters. Plants growing under nano-NiO stress showed an overproduction of superoxide anion (O₂^.-), which favored the occurrence of oxidative stress and the enhancement of lipid peroxidation (LP), but the co-treatment with nano-SiO₂ reverted this tendency, generally lowering or maintaining the levels of LP and stimulating the redox pathway of thiols. The evaluation of the antioxidant (AOX) system revealed that nano-NiO induced the accumulation of proline, along with a decrease in ascorbate in leaves. Furthermore, superoxide dismutase (SOD) activity was significantly enhanced and catalase (CAT) and ascorbate peroxidase (APX) seemed to have a pivotal role in H₂O₂ detoxification in leaves and roots, respectively. The response of the AOX system was even more prominent upon nano-SiO₂ co-exposure, reinforcing the ameliorating functions of this nanomaterial. Overall, the present study highlighted the protective role of nano-SiO₂ in barley plants under nano-NiO stress, possibly due to the Si-mediated protection against oxidative stress, by a more proactive performance of the plant AOX system.

Keywords: Antioxidant system; Barley plants; Nickel oxide nanomaterial; Oxidative stress; Photosynthesis; Silicon dioxide nanomaterial.

MeSH terms

Antioxidants / metabolism
Ascorbate Peroxidases / metabolism
Catalase / metabolism
Hordeum / drug effects*
Hordeum / physiology
Hydrogen Peroxide
Lipid Peroxidation
Nanostructures*
Nickel / toxicity*
Oxidative Stress*
Photosynthesis
Plant Leaves
Silicon Dioxide / chemistry*
Superoxide Dismutase / metabolism

Substances

Antioxidants
Silicon Dioxide
Nickel
Hydrogen Peroxide
nickel monoxide
Ascorbate Peroxidases
Catalase
Superoxide Dismutase