Systemic acquired silencing: transgene-specific post-transcriptional silencing is transmitted by grafting from silenced stocks to non-silenced scions.
Using grafting procedures, we investigated the transmission of co-suppression of nitrate reductase and nitrite reductase host genes and transgenes and of post-transcriptional silencing of a uidA transgene encoding glucuronidase in tobacco. We demonstrate that silencing is transmitted with 100% efficiency from silenced stocks to non-silenced scions expressing the corresponding transgene. Transmission is unidirectional from stock to scion, transgene specific, locus independent and requires the presence of a transcriptionally active transgene in the target scion. The transmission of co-suppression occurs when silenced stocks and non-silenced target scions are physically separated by up to 30 cm of stem of a non-target wild-type plant. Taken together, these results suggest that a non-metabolic, transgene-specific, diffusable messenger mediates the propagation of de novo post-transcriptional silencing through the plant.
Palauqui
J C
JC
Laboratoire de Biologie Cellulaire, INRA, Versailles, France.
Elmayan
T
T
Pollien
J M
JM
Vaucheret
H
H
D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D018014:Gene Transfer Techniques; D017343:Genes, Plant; D005966:Glucuronidase / Q000235:genetics; D050901:Nitrate Reductase; D009565:Nitrate Reductases / Q000235:genetics; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D013489:Suppression, Genetic; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics / Q000378:metabolism
D018076:DNA, Complementary; D018744:DNA, Plant; D012333:RNA, Messenger; D018749:RNA, Plant; D009565:Nitrate Reductases; D050901:Nitrate Reductase; D005966:Glucuronidase