Tomato protein Rx4 mediates the hypersensitive response to <i>Xanthomonas euvesicatoria</i> pv. <i>perforans</i> race T3

Bacterial spot, which is caused by several Xanthomonas species, an economically important disease in tomato (Solanum lycopersicum). Great efforts have been made for the identification of resistant sources and genetic analysis resistance. However, development commercial varieties slow due to existence multiple species pathogen a poor understanding resistance mechanism tomato. The current study revealed that Rx4 gene encodes nucleotide-binding leucine-rich repeat protein wild Solanum pimpinellifolium specifically recognizes confers hypersensitive response (HR) euvesicatoria pv. perforans race T3 expressing AvrXv3 avirulence protein. Complementation susceptible line Ohio 88119 using transgenic approach resulted HR, whereas knockout through CRISPR/Cas9 editing lines Hawaii 7981 PI 128216 led non-HR T3. Transcription was not induced presence Furthermore, did show physical interaction with but interacted SGT1-1 RAR1. Virus-induced silencing RAR1 PI128216 suppressed HR Taken together, our confirms conferring bacterial spot reveals potential roles as signals Rx4-mediated HR. This discovery represents step forward may implications plant–bacterial interactions.