Exploring the potential of green synthesized cerium oxide nanoparticles in mitigating chromium toxicity in maize

Problem: Chromium (Cr) contamination in agricultural soils poses a significant threat to maize productivity and food security, necessitating the development of innovative strategies to enhance Cr tolerance and mitigate its toxic effects on plant growth and development. Objective: The aims of current study are the green synthesis of cerium oxide nanoparticles (CeO2 NPs) using Jasminum officinale L. plant extract and their application to alleviate chromium stress in maize plants. Methods: Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and elemental mapping methods were used to characterize the synthesized CeO2 NPs. The cerium oxide NPs (0, 25, 75 and 100 mg/L) treatment levels applied through foliar and seed priming to check growth, physiological responses and metal uptake by maize plants and a fully random design was used to set up a factorial experiment. Results: The findings showed that foliar application of 100 mg/L CeO2 NPs resulted in an improvement in the plant height (43 %), shoot fresh plant (41 %) and root fresh weight (84 %), and total chlorophyll concentrations (67 %) in maize plants as compared to seed priming (as 25, 32, 40 and 43 % respectively). It also effectively enhanced antioxidant enzymes including super oxide dismutase (75 %) and peroxidase (79 %). In maize plants, by foliar application over the control, CeO2 NPs reduce electrolyte leakage (53 %), malondialdehyde contents (32 %), and chromium content in roots (70 %) under chromium stress. Conclusion: Therefore, these results suggested that increase in the concentration of CeO2 NPs more efficiently 100 mg/L has high ability against chromium stress and act as a promising solution to reduce metal concentration, enhance maize growth and promote sustainable agriculture. Significance: This study’s implications for future research on CeO2 NPs include elucidating their mechanisms in plant stress tolerance, exploring interactive effects with heavy metals, and expanding their use in plant stress management. Furthermore, this finding develops a novel strategy for improving maize cultivation in Cr-contaminated soils, contributing to sustainable agriculture and food security.