Johnsongrass mosaic virus Contributes to Maize Lethal Necrosis in East Africa
Stewart LR1, Willie K2, Wijeratne S3, Redinbaugh MG4, Massawe D5, Niblett CL6, Kiggundu A7, Asiimwe T8.
- Corn, Soybean, and Wheat Quality Research Unit, United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Wooster, OH 44691; and Department of Plant Pathology, The Ohio State University, Wooster 44691.
Corn, Soybean, and Wheat Quality Research Unit, USDA-ARS.
Molecular and Cellular Imaging Center, The Ohio State University.
Corn, Soybean, and Wheat Quality Research Unit, USDA-ARS, and Department of Plant Pathology, The Ohio State University.
Department of Plant Pathology, The Ohio State University.
Venganza, Inc., St. Augustine, FL 32080.
National Agricultural Research Organization, Kampala, Uganda.
Biotechnology Program, Rwanda Agriculture Board, Airport Road 5016, Kigali, Rwanda.’
Maize lethal necrosis (MLN), a severe virus disease of maize, has emerged in East Africa in recent years with devastating effects on production and food security where maize is a staple subsistence crop. In extensive surveys of MLN-symptomatic plants in East Africa, sequences of Johnsongrass mosaic virus (JGMV) were identified in Uganda, Kenya, Rwanda, and Tanzania. The East African JGMV is distinct from previously reported isolates and infects maize, sorghum, and Johnsongrass but not wheat or oat. This isolate causes MLN in coinfection with Maize chlorotic mottle virus (MCMV), as reported for other potyviruses, and was present in MLN-symptomatic plants in which the major East African potyvirus, Sugarcane mosaic virus (SCMV), was not detected. Virus titers were compared in single and coinfections by quantitative reverse transcription-polymerase chain reaction. MCMV titer increased in coinfected plants whereas SCMV, Maize dwarf mosaic virus, and JGMV titers were unchanged compared with single infections at 11 days postinoculation. Together, these results demonstrate the presence of an East African JGMV that contributes to MLN in the region.