A New Window into Transgene Silencing in Plants: mechanisms of copy-number independent, 5' sequence dependent, post-transcriptional silencing in a complex polyploid. Silencing of introduced genes is a major problem limiting plant molecular improvement. Sugarcane, a complex polyploid, shows the most efficient transgene silencing ever observed in plants. Silencing operates on the RNA, depends on the upstream sequence of the gene, and is independent of copy number. Other plant species develop endop ....A New Window into Transgene Silencing in Plants: mechanisms of copy-number independent, 5' sequence dependent, post-transcriptional silencing in a complex polyploid. Silencing of introduced genes is a major problem limiting plant molecular improvement. Sugarcane, a complex polyploid, shows the most efficient transgene silencing ever observed in plants. Silencing operates on the RNA, depends on the upstream sequence of the gene, and is independent of copy number. Other plant species develop endopolyploidy with age, and show unpredictable or patchy silencing. We speculate that differential silencing is a natural control mechanism in the exploitation of polyploidy in plants. The sugarcane system provides an exceptional opportunity to identify the sequences that trigger and protect from silencing, and to develop approaches to avoid the problem.Read moreRead less