Experimental evolution of Tobacco etch virus in transgenic plants

We experimentally addressed the evolution of Tobacco etch virus (TEV) in transgenic Nicotiana tabacum plants expressing the viral replicase, NIb. We found that TEV missing the NIb gene, which is incapable of autonomous replication in wild-type plants, had a higher fitness than the full-length TEV in the transgenic plants. Moreover, when the full-length TEV was evolved by serial passages in transgenic plants, we observed genomic deletions within Nib, and in some cases the adjacent cistrons, starting from the first passage.