Identification of Rsv3 Candidate Gene Conferring Resistance to Soybean Mosaic Virus Strain G5H

Rsv3 which confers strain specific resistance to soybean mosaic virus (SMV) was previously mapped between markers AxxxF/R and MxSat in chromosome 14 of the soybean [Glycine max (L.) Merr.] cultivar L29. From genome database derived from the soybean William 82 (phytozome.net), there are 5 different NBS-LRR sequences between the flanking markers. Among those candidates, only one full-length cDNA clone of the Glyma14g1 was successfully cloned from total RNA from leaves of the soybean L29 which was pre-inoculated by SMV strain G5H. We could not clone cDNAs for the other 4 NBS-LRR candidate genes which might suggest significantly low or no expression of these 4 genes upon SMV strain G5H infection. Upon co-inoculating the expression clones of this cloned candidate gene and SMV strain G5H on primary leaves of the Rsv3-free soybean cultivar Lee74, the infectivity of the SMV G5H strain was significantly attenuated in local and systemic leaves. Altogether these results suggest that the cloned candidate gene Glyma14g1 might be the resistance gene Rsv3 which confers resistance response against SMV G5H strain.