Multi‐Stimuli‐Responsive Hydrogen‐Bonded Organic Frameworks Nanocarriers Enable Targeted Fungicide Release and Plant Immune Regulation

ABSTRACT Precision plant protection requires carriers that couple crystalline order with context‐responsive release. Hydrogen‐bonded organic frameworks (HOFs) offer ordered, metal‐free porosity and programmable host–guest interactions to realize this goal. We therefore built a multi‐stimuli‐responsive system (PYR@PFC‐1‐F@HACC) using the fluorinated HOF PFC‐1‐F as a pesticide carrier and label‐free in planta fluorescent marker. Pyraclostrobin (PYR) was encapsulated in PFC‐1‐F with ∼30 wt.% loading, and the resulting composite was surface‐coated with chitosan quaternary ammonium salt (HACC). The HACC shell imparts leaf adhesion and biointerface compatibility, thereby enabling enzyme/reactive oxygen species (ROS)/pH‐triggered, site‐specific release of the fungicide while suppressing leakage near neutrality. Under pathogen‐mimicking conditions, the composite shows hierarchically programmed, multi‐stimuli‐responsive release with diffusion‐dominated kinetics. Antifungal activity follows a dual pathway‐membrane disruption together with ROS‐associated oxidative stress‐accompanied by host‐defense remodeling. In planta, the platform curtails lesion development, reduces pathogen adhesion/invasion, and exhibits robust foliar retention with acropetal transport. Standard biosafety assays show no significant adverse effects at working doses on peanut seed germination, zebrafish, earthworms, or silkworms. Overall, this study delivers a generalizable, sustainable nanocarrier for precision management of soil‐borne crop diseases.