Comparison of phytotoxic effects of bio-synthesised copper oxide nanoparticle and ionic copper on Elodea canadensis

This study aims to investigate the phytotoxic effects of both Punica granatum peel extract directed copper oxide nanoparticles (CuONPs) and copper nitrate on Elodea canadensis. The CuONPs were characterised by UV–visible spectroscopy (UV-Vis), Dynamic Light Scattering (DLS), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Fourier Transform Infrared (FT-IR) Spectroscopy. The ratio of photosynthetic pigments, total soluble protein, malondialdehyde (MDA), catalase (CAT), ascorbate peroxidase (APX), and copper accumulation in the E. canadensis was determined to evaluate the phytotoxicity of the CuONPs and copper nitrate on E. canadensis. The significant improvements were observed in the growth rate of E. canadensis, chlorophyll a and b, carotenoid contents, and total soluble protein in the E. canadensis when it was exposed to the CuONPs. Additionally, CAT and APX activities and MDA contents were enhanced by accumulation of the CuONPs into the E. canadensis. These results suggested that oxidative stress was alleviated, owing to the result of an increase in the antioxidants such as CAT and APX, with an increase in the concentration of the CuONPs. Finally, the findings of this study show that copper nitrate has many negative effects on E. canadensis compared bio-synthesised CuONPs.

本研究旨在探究石榴皮提取物介导的氧化铜纳米颗粒（CuONPs）与硝酸铜对加拿大伊乐藻（Elodea canadensis）的植物毒性效应。本研究采用紫外-可见分光光度法（UV-Vis）、动态光散射（DLS）、X射线衍射（XRD）、扫描电子显微镜（SEM）及傅里叶变换红外（FT-IR）光谱法对所制备的CuONPs进行表征。通过测定加拿大伊乐藻体内光合色素比值、总可溶性蛋白、丙二醛（MDA）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）活性以及铜积累量，以评估CuONPs与硝酸铜对加拿大伊乐藻的植物毒性。当加拿大伊乐藻暴露于CuONPs环境中时，其生长速率、叶绿素a与叶绿素b含量、类胡萝卜素含量及总可溶性蛋白水平均得到显著提升。此外，CuONPs在加拿大伊乐藻体内的积累可增强CAT与APX活性以及MDA含量。上述结果表明，随着CuONPs浓度升高，过氧化氢酶与抗坏血酸过氧化物酶等抗氧化剂水平上调，从而缓解了氧化应激。本研究最终发现，与生物合成的CuONPs相比，硝酸铜对加拿大伊乐藻具有诸多负面影响。