FIG 7.

The C-terminal 65 amino acids of WSMV CP are dispensable for virion assembly but are required for cell-to-cell movement. (A) Progressive deletions at the C terminus of CP increasingly debilitated the cell-to-cell movement of WSMV in wheat. GFP fluorescent foci induced by GFP-tagged WSMV mutants with progressive deletions at the C terminus of CP on inoculated wheat leaves at 14 days postinoculation are indicated with arrows. Bars, 500 μm. (B) MIVA assay of WSMV mutants with progressive deletions from the C terminus of CP in agroinfiltrated N. benthamiana leaves at 7 dpa. Partially purified virions from agroinfiltrated N. benthamiana leaves were analyzed by immunoblotting at 7 dpa with an anti-WSMV serum. Note that WSMV with progressive deletions of up to 65 amino acids at the C terminus of CP is capable of virion assembly. The protein size markers used in SDS-PAGE are indicated on the left. (C) Electron micrographs of virions (wild type, WSMV-CPΔC17aa) and virus-like particles (noninfectious, WSMV-CPΔC40aa, WSMV-CPΔC49aa, and WSMV-CPΔC55aa) in partially purified virions of GFP-tagged WSMV (wild type) and the C-terminal deletion mutants from agroinfiltrated N. benthamiana leaves at 7 dpa. Bars, 200 nm.