Submitted to: Research in Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/20/2013
Publication Date: 8/1/2013
Publication URL: http://handle.nal.usda.gov/10113/58414
Citation: Nam, M., Bae, H., Hammond, J., Domier, L.L., Youn, Y., Lee, B., Lim, H. 2013. Seed transmission rates of Bean pod mottle virus and Soybean mosaic virus in soybean may be affected by mixed infection or expression of the Kunitz trypsin inhibitor. Research in Plant Disease. 19(2):114-117. Interpretive Summary: Plant viruses are dispersed through seed-borne infections and by insect feeding. For transmission through seed, viruses need to overcome barriers to entry into developing embryos. For transmission by insects, viruses must withstand insect digestive enzymes. Bean pod mottle virus (BPMV) is transmitted through seed at very low levels, but in one experiment, co-infection of soybean plants with Soybean mosaic virus (SMV) enhanced the seed transmission rate of BPMV. In contrast, the rate of SMV seed transmission was not affected by co-infection with BPMV. In a second preliminary study, the rate of SMV transmission through seed was lower in plants that did not express a proteinase inhibitor normally associated with soybean seed than in normal soybean plants. In this preliminary study, we observed that factors such as dual infection and protease inhibitor expression may affect the frequency of seed transmission of BPMV and SMV. These findings will be of interest to soybean pathologists who are interested in reducing the incidence of virus infection of soybean by interfering with the transmission of viruses through seed.
Technical Abstract: To facilitate their spread, plant viruses have developed several methods for dispersal including insect and seed transmission. While insect transmission requires virus stability against insect digestion, seed-transmitted viruses have to overcome barriers to entry into embryos. Bean pod mottle virus (BPMV) is transmitted through seed at levels typically below 0.1%, but co-infection with Soybean mosaic virus (SMV) enhanced the seed transmission rate of BPMV in one experiment. In contrast, the rate of SMV seed transmission was not affected by BPMV co-infection. In a second preliminary study, the rate of SMV transmission was lower in an isoline of Williams 82 that contained a null mutation for the Kunitz trypsin inhibitor gene than in Williams 82. In this preliminary study, we observed that factors such as protease inhibitor expression and dual infection may affect the frequency of seed transmission of BPMV and SMV.