Identification of aurodox as a plant immunity inducer against suspension culture cells of <i>Arabidopsis thaliana</i> from Ōmura natural product library

When plants are infected with pathogens, they activate their immune systems, resulting in hypersensitive cell death, which to prevents the spread of pathogens. Therefore, the compounds that induce plant immunity (i.e. immunity inducers) can protect plants from pathogens by activating the plant immune system without exhibiting antipathogenic activity, which may decrease the risk of drug resistance. However, the number of marketed plant immunity inducers is limited compared to that of marketed pesticides, and their plant protection efficiency remains insufficient. In this study, we screened for compounds that specifically potentiate pathogen-activated cell death from the Ōmura natural product library using an established high-throughput screening system with cultured suspension cells of Arabidopsis thaliana. Our result show that aurodox potentiate pathogen-activated plant cell death, but exhibits weak antibacterial activity against Pseudomonas syringae pv. tomato, suggesting the potential of aurodox as an inducer of plant immunity.