Visible-Light-Absorbing\nPhotosensitizer Nanostructures\nfor Treatment of Pathogenic Bacteria and Induction of Systemic Acquired\nResistance

Induction\nof systemic acquired resistance (SAR) in plants to control\nbacterial diseases has become an effective solution to the problems\nof agrochemical resistance and ecological environment damage caused\nby long-term and large-scale use of traditional bactericides. However,\ncurrent SAR-inducing compounds are often unable to rapidly eliminate\npathogenic bacteria in infected plant tissues to prevent further spread\nof the disease, severely restraining the potential for extensive application\nin agriculture. Herein, we address the limitations by developing a\nseries of visible-light-absorbing aggregation-induced emission photosensitizers\nsuitable for agricultural use. The photosensitizer (MTSQ2) is modulated\nby molecular engineering to have optimal optical properties, reactive\noxygen species (ROS) generation efficiency, and bacterial targeting\naffinity, thereby exhibiting an effective antibacterial photodynamic\nactivity against the phytopathogenic bacteria Pseudomonas\nsyringae pv <i>tomato</i> DC3000 in the\nmodel plant Arabidopsis thaliana under\nwhite light illumination. Moreover, the ROS produced in situ by MTSQ2\ncan further regulate the ROS-AzA-G3P signaling pathway, thus allowing\nto induce SAR throughout the plant to prevent secondary infections.\nThe current study can provide a feasible strategy for developing desirable\nphotosensitizers to achieve sustainable management of plant diseases.