Plants are able to respond to pathogen attack to restrain development of a systemic infection.
Transgenes with homology to viral sequences were also affected. This phenomenon, which was shown to be mediated by both transcriptional and posttranscriptional mechanisms, might be related to regulation of highly expressed genetic elements. To whom correspondence should be addressed. In accordance with Title 17 U.S.C. Section 107, this material is distributed for research and educational purposes only.