Toxicity and Uptake of CuO Nanoparticles: Evaluation of an Emerging Nanofertilizer on Wheat (Triticum aestivum L.) Plant

Abstract

Wet chemistry was used to produce copper oxide nanoparticles (CuO NPs). The results indicated that most nanoparticles were bacillus-shaped and relatively uniform in size (less than 30 nm). The effect of synthesized CuO NPs on wheat (Triticum aestivum L.) germination and growth parameters was studied and compared to bulk Cu. The results showed that no significant difference was obtained in germination rate among all treatments. Bulk Cu additions significantly affect the mean germination rate and mean germination time. On the contrary, germinability was significantly affected by CuO NPs additions. Seed vigor index was calculated to demonstrate the superior treatment in wheat germination parameters, and the results confirmed that 0.1 mg L−1 of CuO NPs could be successfully used to improve wheat seed germination. Moreover, the general average Cu concentrations in the plant tissue were 139 and 103 mg kg−1 dry weight for bulk and CuO NPs, respectively, indicating the dissolution behavior of CuO NPs. The addition of CuO NPs (0.1 mg L−1) promotes chlorophyll formation equal to 0.5 mg L−1 of the bulk Cu addition. This means using nanoparticles as fertilizer could reduce 80% of traditional fertilizers. Nonetheless, Cu additions in both forms (NPs and bulk) reduce root growth substantially compared to control. The effective toxic dose (EC50) for bulk Cu and CuO NPs was 0.37 mg L−1 and 0.94 mg L−1, respectively. The results indicated that approximately 2.5 times CuO NPs concentration is equal to the toxicity dose of bulk Cu due to lowered CuO NPs dissolution. Our study showed that Cu phytotoxicity is a non-nanosized effect and showed that plant-induced changes under environmentally real conditions should be considered when measuring the dissolution of CuO NPs near wheat plant roots. This study implies that using nano-CuO as a micronutrient amendment has a potential benefit rather than the soluble Cu salt for plant growth.

Mercuric oxide nanoparticles deferred germination and devastated root anatomy of maize

“…To our knowledge, there have been no prior reports on seed germination inhibition due to application of HgO-NPs, while inhibitory impacts of other nano-sized heavy metals on seed germination of several plants have been studied. For example, declines of germination indicators were recorded in wheat treated with CuO NPs (Ibrahim et al, 2022), rice treated with Y2O3-NPs (Zhao et al, 2021) and maize treated with PbS-NPs (Ullah et al, 2020), Al2O3 and TiO2-NPS (Karunakaran et al, 2016). All these studies have consistently shown that the toxicity of the applied NPs increases in tandem with the dose, which aligns with our data.…”

“…Once accumulated in soil, toxic agents such as heavy metal nanoparticles (HM-NPs) inhibit seeds germination and development of early seedlings in several plants (Asadi-Kavan et al, 2020;Seddighinia et al, 2020). In this regard, retardation of germination and growth of young seedlings due to nano-sized heavy metals, such as PbS-NPs (Ullah et al, 2020), CuO-NPs (Ibrahim et al, 2022), Y2O3-NPs (Zhao et al, 2021) and ZnO NPs (Yang et al, 2023), have been studied in maize, wheat, rice and Arabidopsis thaliana, respectively. These authors ascribed the delaying of seed germination and deterioration of seedling growth to: (a) deactivation of seed' amylase and protease via formation of S-Metal-S bridges instead of -SH group in the enzyme' proteins (b) blocking of aquaporins delay the rupture of seed coat and emergence of radical (c) restraining water imbibition and uptake due to metal-induced ionic toxicity (d) generation of free radicals and cellular oxidative damage, (e) decreasing internodal length and plant height and (f) distortion of root structures and disruption of water uptake.…”

Integrated Approaches for Adsorption and Incorporation Testing of Green-Synthesized TiO2NPs Mediated by Seed-Priming Technology in Punica granatum L.

“…In agreement with those results obtained from exposed Mung beans [29] and maize seeds [56], TiO 2 NPs were able to penetrate pomegranate seeds, as confirmed through TEM, XRF, and ICP-OES, which is the first direct evidence of TiO 2 NP uptake in pomegranate seed tissues. Such evidence of TiO 2 internalization by plant tissues is also in accordance with a variety of other metal-based nanoparticles, including Fe 3 O 4 , Au, and Cu nanoparticles [57][58][59].…”

Green chemistry routed sugar press mud for (2D) ZnO nanostructure fabrication, mineral fortification, and climate-resilient wheat crop productivity

“…This appears further encouraging in light of the similar repots highlighting soil organic carbon's role in nutrient mobilisation and environmental sustainability 16 , 31 , 33 . However, amid increasing concerns over the bio and environmental compatibility of the poorly defined nanomaterials and lack of enough information over their mechanism and efficiency, this needs vigorous investigation 37 , 38 .

Figure 9 A schematic diagram showing the whole process from the synthesis of the ZnO NPs to its application; The interaction between negatively charged soil colloidal carbon surface with positively charged ZnO NPs (sheet-like structure); nano surfaces along with other mineral nutrients interactions in soil solution for nutrient uptake efficiency has also been shown.

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