VIEW ARTICLE

Physiology and Biochemistry

Soybean Mosaic Potyvirus Enhances the Titer of Two Comoviruses in Dually Infected Soybean Plants. Jose R. Anjos, Department of Plant Pathology, University of Kentucky, Lexington 40546-0091, Present address: CPAC/EMBRAPA, C. P. 70.0023, BR 020 KM 18, 73.300-Planaltina-D.F., Brazil; Ulla Jarlfors, and Said A. Ghabrial. Department of Plant Pathology, University of Kentucky, Lexington 40546-0091. Phytopathology 82:1022-1027. Accepted for publication 26 March 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/Phyto-82-1022.

Soybean plants dually infected with soybean mosaic potyvirus (SMV) and either one of two comoviruses, cowpea mosaic virus (CPMV) or bean pod mottle virus (BPMV), showed greatly increased symptom severity over that induced by the individual viruses. The titer of the comovirus (but not of SMV) in the dually infected plants was significantly higher than that in singly infected plants. Electron microscopic examination of thin sections of leaves from dually infected plants revealed that both SMV and CPMV (or BPMV) were present in the same cells. Unlike SMV, the potyviruses bean yellow mosaic virus and peanut mottle virus did not interact synergistically with BPMV in dually infected soybean plants. The increase in accumulation of comovirus coat protein and RNA components in dually infected plants compared to singly infected plants was monitored by enzyme-linked immunosorbent assay, western blotting, and RNA dot blot hybridization. The results indicated that the levels of these two viral components increased to the same extent in the dually infected soybean plants.