Nano-Priming of Pea (Pisum sativum L.) Seeds with Iron Oxides Nanoparticles: Transforming Agricultural Practices

Abstract

Nano-priming is an innovative method using nanoparticles of various substances, including metals and their oxides for seed treatment. The aim of this study was synthesis of Fe3O4 nanoparticles (NPs) with various stabilizing agents for potential pea seed nano-priming. For this, Fe3O4 NPs stabilized with ammonia, betaine, catamin, lysine, methylcellulose, and rokanol were synthesized and assessed on pea seeds. Physiological and morphological assessments of pea seeds revealed that stabilization of Fe3O4 NPs with rokanol leads to the best germination and growth effects. Quantum chemical modeling showed that the interaction of rokanol with Fe3O4 occurs through OH– groups of rokanol and surface Fe atoms. Notably, interaction of rokanol with Fe3O4 is energetically favorable (∆E =2749.274 kcal/mol) and chemically stable, which is confirmed by a decrease in the chemical hardness of rokanol molecule from 0.149 eV to 0.044 eV at interaction with Fe3O4. The adsorption energy was -4799.799 kcal/mol, indicating the thermodynamic advantages of the adsorption process. Scanning electron microscopy showed that the surface of Fe3O4 NPs is represented by 0.7-10.8 μm agglomerates of regular shape. The analysis of micrographs revealed that Fe3O4 NPs predominantly exhibit spherical shape with a slight deviation to an ellipsoidal form, with an average particle size of 36-69 nm. X-ray phase analysis demonstrated that the sample of Fe3O4 NPs stabilized with rokanol has a crystalline structure with cubic syngony. Thus, characterization of synthesized samples confirmed that Fe3O4 NPs stabilized with rokanol is the most stable sample, yielding the best results in pea seed nano-priming.