Biogenic Iron nanoparticles mediated Eupatorium odoratum for combating Ralstonia solanacearum: Antibacterial, antibiofilm, and enzymes defences modulation

Background and Aim Ralstonia solanacearum is a highly destructive soil-borne bacterial pathogen responsible for bacterial wilt disease in Solanum lycopersicum . Its pathogenic success is driven by long-term coevolution with host plants under diverse biotic and abiotic environmental pressures. R. solanacearum is one of the most destructive plant bacterial infections, and conventional agrochemicals with therapeutic potential have mostly failed to combat it. Furthermore, the overuse and careless use of chemical pesticides has created lasting organic residues and hastened the establishment of resistant bacterial strains, endangering ecological sustainability. The aim was synthesis of Biogenic Iron nanoparticles using Eupatorium odoratum for combating Ralstonia solanacearum . Methods An eco-friendly green synthesis approach was employed to fabricate (FeNPs) using Eupatorium odoratum L. leaf extract as both a reducing and stabilizing agent. FeNPs were evaluated for their antibacterial and antibiofilm efficacy against R. solanacearum , as well as for their ability to modulate host defense-related enzyme expression following FeNP treatment. Results UV–visible spectroscopy confirmed the successful biogenesis of FeNPs, with characteristic absorbance observed 372 nm. Fourier transform infrared (FTIR) spectroscopy revealed the involvement of plant-derived biomolecules in nanoparticle formation and stabilization. Scanning electron microscopy (SEM) analysis revealed predominantly spherical nanoparticle morphology with average size 9.2 nm. Antibacterial assessment showed a maximum inhibition zone of 17.4 ± 0.3 mm at a FeNPs concentration of 250μg/mL. Additionally, molecular interaction studies were conducted to evaluate the binding affinity of FeNPs with key protein targets (PDB IDs: 2P3X, 3F5J, 6AT7, and 5L86), providing mechanistic insights into their antibacterial activity. Conclusion These findings suggest that FeNPs represent a promising and sustainable alternative strategy for the management of R. solanacearum infections.