p ‐Cymene‐Loaded Sucrose‐Functionalized Carbon Dots as Phloem‐Targeted Nanocarriers for Precision Control of Kiwifruit Canker

This study was designed to develop a phloem‐targeted nanopesticide (PC@suc‐β‐cyclodextrins [β‐CDs]) to combat the vascular invasion of Pseudomonas syringae pv. actinidiae (Psa), the causative pathogen of kiwifruit canker. Carbon quantum dots were functionalized with sucrose and β‐CD and then loaded with p ‐cymene (PC). Remarkably, PC@suc‐β‐CDs exhibited a spherical shape (21.5 nm) and a drug‐loading capacity of 15.2%. They also demonstrated improved antibacterial activity (EC ₅₀  = 4.13 mg/L) against Psa, surpassing a conventional PC emulsion in water, with sucrose modification significantly enhancing their accumulation in the phloem (as visualized via confocal laser scanning microscopy). In pot trials, 300 mg/L PC@suc‐β‐CDs achieved a disease control efficiency of up to 84.75%, which is comparable to that of a commercial 2% kasugamycin aqueous solution, along with maintaining >98% cell viability in LO2 cells. Overall, the proposed sucrose‑guided nanodelivery system (PC@suc‐β‐CDs) represents a promising strategy for developing precision delivery systems to manage vascular‐restricted plant diseases.