Polynorbornene Spray Coating to Enhance Plant Health

Bacterial infections in plants threaten oxygen production, food security, and economic stability, challenges exacerbated by biotic and abiotic stresses. Innovative approaches are urgently needed to protect plant health. Synthetic macromolecule systems have previously advanced protection in the biomedical field but plant-specific strategies remain underexplored. This study describes an antibacterial polymer synthesized through ring-opening metathesis polymerization using a norbornene quaternary pyridinium monomer and its application to living Nicotiana benthamiana plants via spray coating. The polymer displayed antibacterial efficacy, as evidenced by inhibition of microbial growth in liquid media, against Escherichia coli and Staphylococcus aureus, as well as inhibition of Agrobacterium infection in planta. Postapplication plant health was confirmed by measuring chlorophyll content and reactive oxygen species levels. Additionally, the coated plants exhibited enhanced drought resistance. These findings underscore the polymer’s efficacy in mitigating bacterial infections while preserving plant health, offering a viable strategy for integrated disease and drought management.