A candidate gene for the determination of rice resistant to rice false smut

In recent years, rice false smut (RFS) has grown from being a minor to a major disease affecting rice productivity. The genetic basis of the host's defense against RFS is currently under-researched. In this study, a rice variety Nanjing11 with stable resistance to RFS from years under naturally infected field condition was identified. The genetic analysis showed that the RFS resistance of Nanjing11 was controlled by a single dominant gene, tentatively termed as false smut resistance 1 (FSR1), which was mapped to a 220-kb interval on the long arm of chromosome 1 by using an F-2 population bred from the cross Nanjing11 (RFS resistant) x CG3 (RFS susceptible). In this 220-kb region, DNMT2 (LOC_Os01g42630) was considered the most likely candidate gene for the RFS resistance of Nanjing11 on the basis of sequence variation and transcriptional responses to Ustilaginoidea virens infection. The result of this study lays the foundations for cloning and functional analysis of FSR1 and application of this gene.