Abstract
We study RNA-mediated TGS to understand effects of siRNA on various genes in rice. RNA-mediated TGS is the chromatin-based gene silencing, triggered by siRNA which contains sequences identical to promoter regions. We produced transgenic rice plants which accumulated promoter-derived siRNAs. We chose a 35S::GFP as a target transgene and OsRac genes as endogenous target genes. Our results indicated that 35S::GFP was silenced, but endogenous OsRac genes were not silenced. However, OsRac target promoter DNA also were methylated de novo, like a 35S target promoter. In addition, results of ChIP analysis of both transgene and endogenous target promoter indicates that degree of histone H3 acetylation and H3 methyl-lysine 4 was lower in 35S promoter. These results suggest that histone modification, but not DNA methylation, is associated with RNA-mediated TGS of the transgene.
