Chimeric, Infectious, and Stable Virus Transcripts to Study RNA Silencing in Dark Green Islands

Dark green islands (DGIs) form in some plant virus infections as areas that are resistant to infection. This resistance has been demonstrated to act through a sequence-specific, RNA degradation mechanism termed RNAi. In addition to the virus that induces the initial DGI, a second, infectious virus transcript carrying additional sequence of the initial virus can be used to dissect the RNAi mechanism of DGIs. The methods used to create stable, infectious transcripts that can carry heterologous sequences are described.