Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2001
Publication Date: N/A
Technical Abstract: The infectivity of monomeric clones of maize streak virus (MSV) was tested using vascular puncture inoculation (VPI). VPI is an effective technique for mechanical transmission of viruses to maize (<i>Zea mays</i> L.) kernels that uses a jeweler's engraving tool to drive minuten pins through virus inoculum and into the scutellum of germinating kernels. The source of inoculum was native plasmid DNA containing either a single copy of the MSV genome (MSV monomer) or a head to tail dimer of the MSV genome (MSV dimer) cloned into the BamHI site of pUC19. VPI of kernels with the MSV dimer incited infection in 38+/-12% of inoculated plants. In contrast, VPI with the MSV monomer produced no infection. However, if the MSV monomer was digested with BamHI prior to VPI, 16+/-3% of plants became infected. Thus, monomers of the MSV genome were infectious after the pUC19 vector sequences were removed. Extracts of systemically infected leaves from plants inoculated with MSV dimer and the BamHI-digested MSV monomer were equally infectious suggesting the inocula produced similar systemic infections.