|Bowen, Charles - Roger|
Submitted to: Phytopathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/19/2010
Publication Date: 6/1/2011
Publication URL: hdl.handle.net/10113/50077
Citation: Domier, L.L., Hobbs, H.A., Mccoppin, N.K., Bowen, C.R., Steinlage, T.A., Chang, S., Wang, Y., Hartman, G.L. 2011. Multiple loci condition seed transmission of Soybean mosaic virus in soybean. Phytopathology. 101:750-756. Interpretive Summary: Infection of soybean plants by Soybean mosaic virus (SMV) can cause significant reductions in seed production and quality. SMV is transmitted from plant to plant by aphids and from one generation to the next through virus-infected seeds. Because seed-borne infections are the primary sources of inoculum for SMV infections in North America, host-plant resistance to seed transmission can limit the pool of plants available to serve as sources of inoculum. In this study we showed that regions from two different soybean chromosomes are required for high levels of resistance to transmission through seed. The same two regions also contained genes that made soybean plants resistant to the seed discoloration that is often caused by SMV infections and is one of the major losses in seed quality associated with SMV infections. Chromosomal regions associated with SMV seed transmission and seed discoloration contained genes involved in basal anti-viral defenses and regulation of gene expression. These results will be of interest to scientist working to develop virus-resistant soybean lines and/or understand the mechanisms by which some viruses are able to invade embryonic tissues.
Technical Abstract: Infection of soybean plants with Soybean mosaic virus (SMV), which is transmitted by aphids and through seed, can cause significant reductions in seed production and quality. Because seed-borne infections are the primary sources of inoculum for SMV infections in North America, host-plant resistance to seed transmission can limit the pool of plants that can serve as sources of inoculum. To examine the inheritance of SMV seed transmission in soybean, crosses were made between plant introductions (PIs) with high (88799), moderate (60279) and low (548391) rates of transmission of SMV through seed. Four populations of F2 plants were inoculated with three SMV isolates, and percent seed transmission was evaluated in grow outs of F3 seedlings. In these crosses, SMV seed transmission segregated as if conditioned by two or more genes. One recombinant inbred line population derived from a cross between PIs 88799 and 548391 was evaluated for segregation of SMV seed transmission, seed-coat mottling and simple sequence repeat markers. Chromosomal regions on linkage groups C1 and C2 were significantly associated with both transmission of isolate SMV 413 through seed and SMV-induced seed coat mottling, and explained approximately 42.8% and 46.4% of the variability in these two traits, respectively. Chromosomal regions associated with seed transmission and seed-coat mottling contained homologues of Arabidopsis genes DCL3 and RDR6, which encode enzymes involved in RNA-mediated transcriptional and posttranscriptional gene silencing.