Metal oxide nanoparticles as promising agents for triggering defense mechanisms in plants against bacterial diseases

Abstract

Metal oxide nanoparticles (MONPs) have received much attention in recent years because of their potential to improve plant defense mechanisms against bacterial infections. MONPs interact with plant tissues in a way that activates natural immune responses, making them an intriguing alternative to standard chemical pesticides. MONPs such as zinc oxide (ZnO), copper oxide (CuO), and titanium dioxide (TiO₂) can cause oxidative stress in plant cells and generate reactive oxygen species (ROS), which activate defense-related signaling pathways.Reactive oxygen species (ROS) can be directly scavenged by nanoparticles, which can also act as transporters to more efficiently deliver traditional antioxidants to target areas or mimic natural antioxidant enzymes.In addition to their ability to stimulate plant immune responses, MONPs have inherent antibacterial characteristics that can directly impede bacterial development. When applied to plants, MONPs penetrate the cell walls and membranes of both plant and bacterial cells, disrupting bacterial cell integrity and restricting pathogen growth. This dual effect, which stimulates plant defenses while directly targeting pathogens, improves the overall resistance of plants to bacterial infections. Furthermore, the ability of metal oxide nanoparticles to elicit systemic acquired resistance (SAR) makes them an appealing alternative for sustainable disease control, thereby reducing the reliance on chemical pesticides and minimizing their negative environmental consequences. MONPs have a promising future in plant protection, with continuing research aimed at optimizing their size, surface properties, and delivery techniques to improve their efficacy and durability.