Investigation of the Effect of Iron-Based Nanoparticles on Rice under Temperature Stress

As the global climate environment continues to change, the frequency of extreme temperature events is expected to increase. The temperature stress environments of low and high temperatures can directly or indirectly affect the growth of rice (Oryza sativa L.), affecting its normal metabolism, which in turn can have an impact on yields and threaten global food security. Agriculture needs new technologies to mitigate temperature stress and improve grain yield and quality. In this study, two iron (Fe)-based nanoparticles (NPs), Fe₂O₃ NPs and Fe₃O₄ NPs, as well as groups of Fe ions corresponding to the Fe concentration, were selected for hydroponic experiments on rice under normal (25°C), low (20°C), and high (38°C) temperature conditions, respectively. It was found that low and high temperature stresses reduced stem length (3 and 7.02%), root length (49.53 and 26.01%), and aboveground (52.49 and 26.04%) and belowground biomass (53.94 and 35.22%) in rice. Both Fe₂O₃ NPs and Fe₃O₄ NPs could promote root development by nutrient uptake, transferring to the aboveground to enhance photosynthesis, and promoting the activity of antioxidant enzymes to eliminate oxidative stress to alleviate the stress of low and high temperatures. The Fe₃O₄ NPs were more stable and had obvious effects at both high and low temperatures.