Comparative Study of Green-Synthesized and Market-Procured CuO and FeO Nanoparticles on the Growth and Stress Tolerance in Rice Seedlings

The widespread use of nanoparticles (NPs) resulting from industrial activities has led to significant environmental challenges, including biodiversity loss, climate change, soil pollution (both agricultural and saline), and contamination of water bodies. Iron oxide nanoparticles (FeO NPs) and copper oxide nanoparticles (CuO NPs) are extensively used across various industries such as biomedical devices, glass manufacturing, paint production, and as doping materials in semiconductors due to their unique properties. This widespread application necessitates an assessment of their impact on plant growth and agricultural systems.In this study, we investigated the comparative effects of green-synthesized versus market-procured CuO and FeO NPs on rice seedlings. The green synthesis of CuO and FeO NPs was achieved using a plant extract from Amragandhi Haridra (Curcuma amada). Several analytical techniques, including ultraviolet spectrometry (UV-vis), particle size analysis (PSA), X-ray diffraction (XRD), field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FE-SEM EDX), and Fourier transform infrared spectroscopy (FTIR), were employed to characterize the size, shape, functional groups, and crystalline structure of the green-synthesized nanoparticles.Our findings revealed that market-procured CuO NPs (50 µM) and FeO NPs (200 µM) significantly impaired rice seedling growth, reducing shoot length, root length, and fresh weight. These nanoparticles also decreased the levels of chlorophyll a, chlorophyll b, and carotenoids compared to green-synthesized CuO (50 µM) and FeO NPs (200 µM). Moreover, market-procured nanoparticles at the same concentrations induced the generation of reactive oxygen species (ROS), disrupting plant metabolism by interfering with photosynthesis, respiration, and electron transport activities. In contrast, green-synthesized CuO and FeO NPs at lower concentrations (50 µM) enhanced plant growth and offered protection against oxidative stress.In conclusion, these findings highlight the superior potential of green-synthesized NPs in protecting rice crops from oxidative stress, in contrast to market-procured NPs, representing a significant advancement toward sustainable agricultural practices.