Abstract

Boron (B) is an essential micronutrient that improves plant growth, development, and performance, but it can be toxic to crops at high concentrations. Recent studies indicate that applying iron nanoparticles (FeNPs) to plants can improve various plant yields and resistance to metalloid stress. FeNPs can modulate the toxic effects of metalloids through FeNP-induced antioxidant induction and downregulation of metal transporters, thereby reducing ROS generation and oxidative damage. In the present study, magnetite (Fe3O4) NPs were synthesized via a green method, and the mitigation of B toxicity was investigated using combined treatments of Fe-based NPs and B in hydroponic lettuce cultures. The results showed improved plant performance with Fe3O4NPs (10 mg L-1), including increases in chlorophyll content (22%) and fresh weight (66%) and a reduction in oxidative stress (66%). The leaf's photosynthetic rate and Fe fortification also significantly increased in response to the combined treatments. Applying Fe3O4NPs as an additive to hydroponic media can reduce and modulate B toxicity in lettuce.