Abstract
In plants, RNA silencing induced by highly transcribed sense transgenes makes it difficult to express the transgene at high level. SDE1 of Arabidopsis thaliana is an RNA-dependent RNA polymerase that synthesizes an anti-sense RNA from an RNA template and plays an essential role in the transgene-induced RNA silencing. To obtain transgenic lines that express transgene at high level, we produced Arabidopsis transformant in which expression of sde1 is reduced.
We cloned a 1500-bp DNA fragment including the first intron of Arabidopsis sde1 and ligated its 5'-1100-bp fragment inversely at the 3'-end, to produce an intron-spliced double-stranded RNA. The construct was introduced via Agrobacterium and the expression of the sde1 gene in the transformed Arabidopsis was examined by RT-PCR using primers specific to sde1. The results indicated decrease in the level of sde1 mRNA in the tranformant, suggesting the possibility of suppression of RNA silencing.
