Isolation and validation of a candidate Rsv3 gene from a soybean genotype that confers strain-specific resistance to soybean mosaic virus

Soybean mosaic virus (SMV), a member of the genus Potyvirus, significantly reduces soybean production worldwide. Rsv3, which confers strain-specific resistance to SMV, was previously mapped between the markers A519F/R and M3Satt in chromosome 14 of the soybean [Glycine max (L.) Mem] genotype L29. Analysis of the soybean genome database revealed that five different NBS-LRR sequences exist between the flanking markers. Among these candidate Rsv3 genes, the full-length cDNA of the Glyma.14g204700 was successfully cloned from L29. Over-expression of Glyma.14g204700 in leaves inoculated with SMV inhibited viral infection in a soybean genotype lacking Rsv3. In addition, the transient silencing of the candidate gene caused a high accumulation of an avirulent strain in L29 carrying Rsv3. Our results therefore provide additional line of evidence to support that Glyma.14g204700 is likely Rsv3 gene that confers strain-specific resistance to SMV.