Magnetite (Fe₃O₄) Nanoparticles Alleviate Growth Inhibition and Oxidative Stress Caused by Heavy Metals in Young Seedlings of Cucumber (Cucumis Sativus L)

¹ College of Resources and Environmental Sciences, China Agricultural University, Beijing 100093, China
² Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China

^a alexandrekonate28@gmail.com
^b hexiao@ihep.ac.cn
^c ruiyukui@163.com
^d zhangzhy@ihep.ac.cn
^* Correspondng author: ruiyukui@163.com

Abstract

Accumulation of heavy metals in the ecosystem and their toxic effects through food chain can cause serious ecological and health problems. In the present study, experiments were performed to understand how the addition of magnetite (Fe₃O₄) nanoparticles reduces the toxicity caused by Cd, Pb, Cu, and Zn in cucumber plants. Plant growth parameters, lipid peroxidation, and antioxidant enzymes were measured in seedling samples treated with either metals or metals supplemented with Fe₃O₄ to demonstrate the reduction in metal-induced oxidative stress conferred by Fe₃O₄. Results showed that the toxic effect of metals on seedling growth parameters can be arranged in the rank order of inhibition as follows: Cu > Cd > Zn > Pb. Exposure to metals significantly decreased the seedlings growth, the activities of superoxide dismutase (SOD) and peroxidases (POD), while the malondialdehyde (MDA) content significantly increased in cucumber seedlings. The reducing activity of nano-Fe₃O₄ against heavy metals stresses was confirmed in this study by the decrease in MDA content. The correlation between the decrease of MDA concentration and the increase in SOD and POD activities in the presence of nano-Fe₃O₄ suggest that the MDA reduction in the tested seedlings can result from the increased enzyme activity.