title: Mutational analysis of the putative pipo of soybean mosaic virus suggests disruption of PIPO protein impedes movement.
abstract: The presence of a small open reading frame embedded in the P3 cistron of potyvirus turnip mosaic virus, termed "pipo," was recently discovered. We have now studied the putative pipo of soybean mosaic virus (SMV). Introduction of single, or multiple, stop codon mutations at different locations within pipo, without substitution in polyprotein amino acids, did not abolish replication, but restricted the virus to small cluster of cells within the inoculated leaves. Furthermore, extensive mutagenesis of the conserved GA(6) motif at the 5' end of pipo also generated two out of five mutants that remained restricted to small foci of infected cells within the inoculated leaves. Long-distance movement function of the movement-defective PIPO-mutants was not restored following co-inoculation with competent SMV strains. Taken together, the data suggest that the putative pipo of SMV is essential for the virus movement; however, knock out of its expression does not abolish replication.
authors.affiliation: Department of Entomology and Plant Pathology, The University of Tennessee, Knoxville, TN 37996, USA.
authors.forename: R-H
authors.initials: RH
authors.lastname: Wen
authors.forename: M R
authors.initials: MR
authors.lastname: Hajimorad
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D018388:Codon, Terminator; D017124:Conserved Sequence; D004252:DNA Mutational Analysis; D004279:DNA, Viral / Q000235:genetics*; D005796:Genes; D005814:Genes, Viral; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009068:Movement / Q000502:physiology; D016297:Mutagenesis, Site-Directed; D016366:Open Reading Frames; D010935:Plant Diseases / Q000821:virology; D053830:Plant Viral Movement Proteins / Q000235:genetics* / Q000502:physiology; D017800:Potyvirus / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D013025:Glycine max / Q000821:virology*; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
chemical_list: D018388:Codon, Terminator; D004279:DNA, Viral; D053830:Plant Viral Movement Proteins