Transgene silencing in monocots

Plant gene silencing was originally thought to be a quirk of transformation procedures, but is now recognized to be a facet of vitally important gene regulatory systems, present in all organisms. Monocot plants, especially th e grasses, play a foremost role in the agricultural economy of all nations, and their biotechnological manipulation offers great potential for both de veloped and developing countries. Here, we review reported instances of tra nsgene silencing in monocots and relate the processes of transcriptional an d post-transcriptional gene silencing (TGS, PTGS) in perspective to the rap idly burgeoning knowledge of these phenomena in many organisms. Recent find ings include the involvement of an RNA-dependent RNA polymerase and a nucle ase in PTGS systems and the close relationship between methylation and chro matin structure in TGS events.