Carbon-Bound Iron Oxide Nanoparticles Prevent Calcium-Induced Iron Deficiency in Oryza sativa L. 

Iron-based nanocomposites can be a practical solution to combat iron deficiency in calcareous agricultural soil. In the present study, a carbon-bound iron oxide nanoparticle is synthesized by mixing ferric chloride and caffeic acid and tested to correct Ca-inducible Fe deficiency in rice. Physicochemical characterization points that the nanoparticle is carbon-coated semi-crystalline Fe₃O₄. It is found that nanoparticle amendment enhances bioproductivity, photosynthetic electron transport, antioxidant enzyme activity, and Fe accumulation under Ca stress. Reduction in Ca accumulation via physical adsorption, Fe release from the particles, and maintenance of molecular responses related to Fe acquisition were the reasons for the above progressive growth effects. Thus, it is concluded that nanoparticles synthesized in the study act as a potential ameliorant to correct Ca-induced Fe deficiency in rice plants.