Mesoporous Silica Nanoparticles Confer Broad-Spectrum Disease Resistance in Rice via the OsERF3-OsRBOHE-ROS Pathway

Rice is a vital global staple crop, yet its productivity is significantly constrained by various diseases caused by pathogenic microorganisms. Developing efficient and environmentally friendly alternatives to complement or replace conventional chemical pesticides is therefore crucial for sustainable rice production. Mesoporous silica nanoparticles have emerged as promising candidates for plant protection, owing to their unique physicochemical properties and high biocompatibility. However, the efficacy and underlying mechanisms of different mesoporous silica nanoparticles morphologies against major rice diseases remain to be fully elucidated. In this study, we synthesized two types of mesoporous silica nanoparticles with distinct morphologies-spherical (MSN) and virus-like spiky (VMSN) within a plant-absorbable size range. We systematically evaluated their protective effects against southern rice black-streaked dwarf virus (SRBSDV), Bacterial leaf streak (BLS), and Rice sheath blight (RSB). The results demonstrated that both nanoparticles could induce broad-spectrum resistance, with spherical MSN exhibiting superior efficacy in pathogen suppression. Mechanistic investigations revealed that MSN and VMSN differentially up-regulated the expression of the transcription factor OsERF3, which in turn activated its downstream target gene OsRBOHE, leading to a defense-related reactive oxygen species (ROS) burst. Further genetic evidence confirmed that OsRBOHE acts as a positive regulator of rice resistance to both SRBSDV and BLS. Additionally, both nanomaterials displayed favorable leaf wettability, were efficiently absorbed and systemically translocated within rice plants, and showed no adverse effects on seed germination, seedling growth, or key agronomic traits at maturity. In conclusion, this study elucidates the molecular mechanism whereby spherical MSN functions as potent immune primers by preferentially activating the OsERF3-OsRBOHE-ROS signaling axis. Combined with their excellent foliar delivery properties and biosafety, these findings provide a solid theoretical and practical foundation for developing sustainable, nanosilica-based crop protection strategies.