Effects of Copper Oxide Nanoparticles on the Growth of Rice (Oryza Sativa L.) Seedlings and the Relevant Physiological Responses

Abstract

Rice (Oryza sativa L.), a major staple food for billions of people, was assessed for its phytotoxicity of copper oxide nanoparticle (CuO NPs, size < 50 nm). Under hydroponic condition, seven days of exposure to 62.5, 125, and 250 mg/L CuO NPs significantly suppressed the growth rate of rice seedlings compared to both the control and the treatment of supernatant from 250 mg/L CuO NP suspensions. In addition, physiological indexes associated with antioxidants, including membrane damage and antioxidant enzyme activity, were also detected. Treatment with 250 mg/L CuO NPs significantly increased malondialdehyde (MDA) content and electrical conductivity of rice shoots by 83.4% and 67.0%, respectively. The activity of both catalase and superoxide dismutase decreased in rice leaves treated with CuO NPs at the concentration of 250 mg/L, while the activity of the superoxide dismutase significantly increased by 1.66 times in rice roots exposed to 125 mg/L CuO NPs. The chlorophyll, including chlorophyll a and chlorophyll b, and carotenoid content in rice leaves decreased with CuO NP exposure. Finally, to explain potential molecular mechanisms of chlorophyll variations, the expression of four related genes, namely, Magnesium chelatase D subunit, Chlorophyll synthase, Magnesium-protoporphyrin IX methyltransferase, and Chlorophyllide a oxygenase, were quantified by qRT-PCR. Overall, CuO NPs, especially at 250 mg/L concentration, could affect the growth and development of rice seedlings, probably through oxidative damage and disturbance of chlorophyll and carotenoid synthesis.

Efficacy Assessment of Biosynthesized Copper Oxide Nanoparticles (CuO-NPs) on Stored Grain Insects and Their Impacts on Morphological and Physiological Traits of Wheat (Triticum aestivum L.) Plant

“…The toxicity of high concentrations could be attributed to the liberation of Cu ions from CuO-NPs in aqueous solutions, which is a toxicity factor in plants [ 80 ]. Several studies have reported an increase in plant growth criteria in response to the application of CuO-NPs at small concentrations [ 81 , 82 , 83 , 84 ]. Additionally, Yasmeen et al [ 85 ] have reported that the growth of wheat ( Triticum aestivum ) plants were increased when plants were soaked with Cu-NPs.…”

Biodegradable Antimicrobial Food Packaging: Trends and Perspectives

“…Toxicological concerns exist also for copper and copper oxide nanoparticles as studies indicate a strong relation between decreasing nanoparticles size and increasing phytotoxicity [ 271 , 272 , 273 ]. Some recent studies also indicate effects on plastids, mitochondria, protoplasm, and membranes for Hordeum sativum distichum [ 274 ] or Abelmoschus esculentus [ 275 ].…”

Biostimulation and toxicity: The magnitude of the impact of nanomaterials in microorganisms and plants

“…na: data not available. Data and plant species from: [109] Solanum lycopersicum ; [110] Oryza sativa ; [111] Triticum aestivum ; [112] Arachis hypogaea ; [113] Calendula officinalis ; [114] Nicotiana tabacum ; [115] Triticum aestivum ; [116] Vigna unguiculata ; [117] Triticum aestivum ; [118] Solanum lycopersicum ; [119] Oryza sativa ; [120] Raphanus sativus ; [121] Vigna radiata ; [122] Oryza sativa ; [123] Phaseolus vulgaris ; [124] Oryza sativa ; [125] Fragaria × ananassa ; [126] Raphanus sativus . …”