| pubmed-article:20708047 | pubmed:abstractText | Paprika mild mottle virus Japanese strain (PaMMV-J), a member of the genus Tobamovirus, was originally isolated from sweet pepper plants (Capsicum annuum L.). In experimental conditions, PaMMV-J spread more slowly in inoculated leaves of tomato plants and moved to uninoculated upper leaves at a lower frequency than Tomato mosaic virus (ToMV). In this study, we aimed to identify the viral factors responsible for the low efficiency of local and systemic movement of PaMMV-J in tomato plants. Using several viruses formed as chimeras between PaMMV-J and ToMV, we observed that a chimeric virus (Pa-RepL) having the 126- and 183-kDa replicase genes of ToMV could move systemically in tomato plants, similar to ToMV. Furthermore, analysis of a PaMMV-J mutant (PaMMV-1483C) showed that a single nucleotide substitution in 126- and 183-kDa replicase genes of PaMMV-J enhanced the efficiency of local movement of the virus in inoculated leaves to an extent similar to that of ToMV. However, PaMMV-1483C did not spread over the uninoculated upper leaves. In addition, viral RNA accumulation levels in tomato protoplasts inoculated with Pa-RepL and PaMMV-1483C were lower and similar to those of parental PaMMV-J. These results suggest that the 126- and/or 183-kDa replicases or their coding regions are responsible both for inefficient local and for systemic movements of PaMMV-J in tomato plants. | lld:pubmed |
