A Redox‐Responsive Nano‐Immune Coupling Strategy Enables Synergistic Pathogen Eradication and Host Resistance Activation Against Bacterial Wilt

ABSTRACT Here, we develop a redox‐responsive nano‐immune coupling strategy for synergistic control of tomato bacterial wilt. The CuO@MON nanocomposite consists of copper oxide nanoparticles embedded within glutathione‐responsive mesoporous organosilica (MON), enabling selective disassembly in the thiol‐rich bacterial microenvironment. Under in vitro conditions, Ralstonia solanacearum was treated with CuO@MON at concentrations ranging from 0 to 500 mg/L for 24 h, with CuO, MON, and zhongshengmycin as controls. CuO@MON exhibited concentration‐dependent antibacterial activity and higher efficacy than CuO alone, with an EC 50 value of 96.96 mg/L. Mechanistic analyses showed that CuO@MON enhanced intracellular ROS generation (2.054 ± 0.098‐fold increase), promoted glutathione depletion, and induced membrane damage and genomic DNA degradation in R. solanacearum . In tomato plants, CuO@MON treatment (250 mg/L) reduced stem colonization by R. solanacearum by 84.0% after 4 days of inoculation compared with infected controls, while zhongshengmycin achieved a 94.9% reduction as a conventional positive control. Moreover, CuO@MON enhanced defense‐related responses, increasing PR‐1 expression from 400 ± 96‐fold to 533 ± 140‐fold and PR‐5 expression from 340 ± 50‐fold to 807 ± 121‐fold relative to healthy controls. Collectively, CuO@MON integrates pathogen suppression with host defense activation, providing a nano‐immune coupling strategy for sustainable bacterial disease management.