Rice brown spot resistance gene bsr1 also confers resistance to bacterial blight by suppressing sucrose efflux

Using map-based cloning, the team pinpointed bsr1 as a quantitative trait locus for brown spot resistance in rice. A near-isogenic line carrying bsr1 (bsr1-NIL) in the susceptible Koshihikari background showed resistance to brown spot, and further experiments revealed it also confers resistance to bacterial blight. The mechanism involves suppressed sucrose efflux, which likely limits pathogen access to nutrients. This dual resistance is particularly valuable since both diseases cause major yield losses globally. The findings suggest that modulating sucrose transport could be a broad-spectrum strategy for rice disease resistance. Next steps would include testing the gene in other rice varieties and understanding its regulatory network.