A gene are expressed. A section of a protein separation is shown below.
Some plants transformed with pieces of viral genomes are resistant to viral infection.
In certain of these plants, transgene RNA is not detectable. In other cases, methylation is not detected. The gene is being actively transcribed, but no RNA accumulates. Post-transcriptional gene silencing also occurs when the transgene is also present in the viral genome. For example, a potato virus X genome bearing the GUS reporter gene infects wild type plants but will not infect plants that have an active GUS transgene.