A new bacterial blight resistance gene () in the locus confers resistance against pv. in rice.

Rice bacterial leaf blight (BB), caused by pv. (), leads to severe yield losses in rice. Resistance breeding is a sustainable approach to mitigate the impact of this disease. In this study, a novel BB resistance gene, (), was identified in the germplasm line CX315. Genetic analysis revealed that the resistance is conferred by a dominant resistant gene, tentatively named (), which provides broad-spectrum and robust resistance to multiple strains. Using an F population derived from a cross between CX315 and IR24, () was fine-mapped to a 147.7 kb region on the long arm of chromosome 11 flanked by InDel markers M11-588 and M11-602. Gene expression analysis identified three candidate genes out of 13 open reading frames (ORFs) predicted in candidate region. and (), encoding a wall-associated kinase (WAK)-like protein, and , encoding a receptor-like kinase protein, were significantly upregulated in CX315 following inoculation. While is predicted to encode the resistance gene, CRISPR/Cas9-based knockout of did not abolish ()-mediated resistance in the CX315 line, indicating that () confers resistance in a complementary manner. Transcriptome analysis further revealed that oxidative stress response and immune signaling pathways were enriched in CX315 at 48 hours post-inoculation. Together, these findings highlight the potential of () as a valuable genetic resource for improving BB resistance in rice, and the transcriptome data provides molecular insight into the BB resistance response.