A coordinated toolbox strategy integrating direct pathogen suppression, host-associated responses, and microbiome remodeling for crop protection

Although integrated pest management promotes the coordinated use of multiple disease-control tactics, single sprayable formulations that consolidate complementary crop-protection functions remain underdeveloped. Here, we combined semi-rational screening with supramolecular co-assembly to construct a ternary nanoassembly comprising glycyrrhizic acid (GA, a plant-derived amphiphile), magnolol (MN, a plant-derived antifungal phenolic), and Zn 2+ , termed G-M@Zn NPs. Compared with free MN, G-M@Zn NPs enhanced MN photostability by 3.7-fold and increased rainfastness by 2.1-fold, indicating improved formulation persistence under simulated photolytic and wash-off stresses. The nanoformulation exhibited broad-spectrum antifungal activity in vitro against representative phytopathogenic fungi and, in a wheat-spike infection model of Fusarium graminearum , reduced the disease index from 52.5 ± 2.46 in the infected control to 22.3 ± 3.4. Under toxin-inducing conditions, G-M@Zn NPs also reduced deoxynivalenol (DON) accumulation and downregulated key TRI genes. Mechanistic assays linked the antifungal activity of G-M@Zn NPs to fungal membrane injury and mitochondria-associated oxidative stress in F. graminearum , with free MN eliciting qualitatively similar but weaker responses. G-M@Zn NP treatment was also accompanied by host defence-related physiological and metabolic responses involving redox regulation and tryptophan/indole-related pathways, together with treatment-associated shifts in the wheat spike microbiome. Preliminary biosafety assays indicated crop compatibility under the tested conditions and low acute toxicity toward earthworms. Serial-passage assays with F. graminearum showed only a modest increase in EC 50 after eight passages. Overall, this ternary co-assembly provides a strategy for integrating complementary crop-protection functions within a single multifunctional nanoformulation and supports IPM-compatible control of F. graminearum infection in wheat. It may also inform the design of bioinspired nanopesticide systems that combine improved formulation persistence with direct antifungal activity and crop-associated biological responses.