|Redinbaugh, Margaret - Peg|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 6/17/2000
Publication Date: N/A
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 coat protein and RNA in vascular puncture inoculated Pa405 and a susceptible inbred (Oh28) were compared. After inoculation, the viral coat protein and RNA were found in the scutellum and embryo of both inbreds, demonstrating that MDMV-A entered and replicated in Pa405 cells. However, the virus was more invasive in Oh28 suggesting that virus movement was limited in the resistant line. To further characterize limitations to virus movement in Pa405, the MDMV-A genome was cloned and a full-length cDNA construct was inserted downstream of a T3 promoter. Sequence analysis of the genome revealed a polyprotein sequence with similarity to other potyviruses. Transcripts, synthesized from the clone, are being tested for their infectivity in maize. To identify maize proteins involved in the resistance response, a "virus overlay" assay was used to identify several MDMV-binding proteins in both Pa405 and Oh28. Work to identify, characterize and isolate these maize proteins is ongoing.