Analysis The Mechanism Of Antisense Transgene Mediated Gene Silencing

Sense and antisense transgenes have been used to down-regulate genes in plants. Although there is considerable variation in both sense and antisense transformants, have been noted several striking similarities between down-regulation of gene expression by sense and antisense transgenes: (1) Both are remarkably effective and specific for the target gene; (2) Both cause a dramatic reduction in the amount of mRNA that accumulates from the endogenous gene; (3) Both lead to the production of similar fragments of endogenous mRNA (4) Both resist to the virus which has some homologous nucleotide sequences with sense and antisense transgene. It seems that sense transgene silencing and antisense transgene silencing share similar mechanism, however, there are some evidence showing that they may be different in some aspects, such as the different phenotype they cause in petunia. We therefore, proposed to compare the mechanism of sense and antisense silencing. We carry out two different experiments: the first one is to test if antisense GFP can cause release of silencing of existing GFP in gene silencing mutants sde-1, 2, 3. the second one is to check whether or not silencing signal can transfer from antisense induced Aco1 gene silencing stock to Aco1 over expression scion with the reference that systemic silencing is a feature of sense transgene induced gene silencing.