|Redinbaugh, Margaret - Peg|
Submitted to: Plant Biotechnology Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/11/2000
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Maize dwarf mosaic potyvirus (MDMV) causes an important disease in corn worldwide. The disease is controlled primarily through use of resistant hybrids. The maize inbred, Pa405, has a high level resistance to MDMV conferred by a single dominant gene on chromosome 6. To develop an understanding of the resistance mechanism, the distribution of MDMV-A virion protein and RNA in vascular puncture inoculated Pa405 and a susceptible inbred (Oh28) were compared. After inoculation, the virion protein and RNA were found in the scutellum and embryo of both inbreds, demonstrating that MDMV-A entered and replicated in Pa405 cells. Virion protein was detected on the first few leaves of both inbreds with more localization in vascular tissue. However, the virus was more invasive in Oh28 suggesting that virus movement was limited in the resistant line. Subcellular localization of virus in infected leaves was investigated. Transmission electron microscopy of immunogold labeled MDMV indicated that virion protein was found in the cytoplasm and cell walls of both inbreds. More cylindrical inclusion bodies were found in Oh28. To further understand the function and localization of individual MDMV proteins, portions of the genome encoding the helpercomponent/proteinase (HC-Pro), coat protein (CP) and genome-linked protein (VPg) were expressed in E. coli. Antibodies raised against the HC-Pro, CP and Vpg were raised in rabbits. Western blots showed that HC-Pro antibody reacted with a protein in infected leaf extracts, but not healthy plants. Experiments to define the localization of the HC-Pro in MDMV-infected maize tissues are ongoing.