Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 19, 2009
Publication Date: November 1, 2009
Citation: Li, S., Moon, J.S., Lee, S.H., Domier, L.L. 2009. First Report of Soybean Yellow Mottle Mosaic Virus in Soybean in North America. Plant Disease. 93 (11):1214. Interpretive Summary: Soybean is one of the most widely grown oil-seed crops in the world. Virus infections reduce both the quantity and quality of seed harvested. Since it is not possible to cure plants of virus infections, one of the best methods to limit losses caused by viruses is to produce varieties of soybean plants that are resistant. Because soybean plants are susceptible to several different viruses, it is important to identify the virus(es) responsible for disease losses so that targeted breeding programs can be implemented. While it is often possible to identify the virus causing disease symptoms in soybean plants, in a significant number of instances the causal agent can not be identified. A new soybean infecting virus, Soybean yellow mottle mosaic virus (SYMMV), was described earlier in 2008 in Korea. To determine whether SYMMV is present in the United States, sensitive and highly specific assays were designed to detect SYMMV genetic materials contained in 17 soybean germplasm lines (including five from Korea) in Mississippi in August 2008. Characterization of the genome of the Mississippi isolate of SYMMV showed that it was 95% identical to the Korean SYMMV isolate. This is the first report of Soybean yellow mottle mosaic virus in North America. This assay will allow scientists to determine the distribution of SYMMV in North America.
Technical Abstract: Soybean yellow mottle mosaic virus (SYMMV) is a soybean-infecting virus recently described in Korea that initially induces bright yellow mosaic on leaves followed by stunting and reduced growth of older leaves. Nucleotide sequence analysis of genomic RNA of the Korean isolate of SYMMV suggested that the virus is a new member of the genus Carmovirus in the family Tombusviridae. To determine whether SYMMV is present in the United States, two pairs of oligonucleotide primers were designed from regions conserved between SYMMV and Cowpea mottle virus (a related and seed-transmitted carmovirus) for use in quantitative real-time reverse transcriptase polymerase chain reaction (QRT-PCR) analyses. In August 2008, about 10 leaflets from 10 plants each of 136 plots were collected without regard for symptoms from a research field in Stoneville, Mississippi that contained 17 plant introductions (including five from Korea) and Williams 82. Samples were grouped into pools of 100 leaves from which total RNA was extracted and analyzed by QRT-PCR. Six of the ten 100-leaf pools produced positive signals with both primer sets. Using primers corresponding to nt 1-21 and complementary to nt 3483-3508 and corresponding to nt 3366-3391 and complementary to nt 4000-4009, two overlapping DNA fragments representing the entire SYMMV genome were amplified and sequenced. The 4009 nt sequence (Genbank Accession #____) was 95% identical to the Korean SYMMV isolate and 65% identical to Cowpea mottle virus. This is the first report of Soybean yellow mottle mosaic virus in North America.