| dc.description.abstract | In plants, transgenes with inverted repeats are used to in-
duce efficient RNA silencing, which is also frequently induced
by highly transcribed sense transgenes. RNA silencing
induced by sense transgenes is dependent on
RNA-dependent RNA polymerase 6 (RDR6), which converts
single-stranded (ss) RNA into double-stranded (ds)
RNA. By contrast, it has been proposed that RNA silencing
induced by self-complementary hairpin RNA (hpRNA)
does not require RDR6, because the hpRNA can directly
fold back on itself to form dsRNA. However, it is unclear
whether RDR6 plays a role in hpRNA-induced RNA silencing
by amplifying dsRNA to spread RNA silencing within
the plant. To address the efficiency of hpRNA-induced
RNA silencing in the presence or absence of RDR6, Wild
type (WT, Col-0) and rdr6-11 Arabidopsis thaliana lines
expressing green fluorescent protein (GFP) were generated
and transformed with a GFP-RNA interference (RNAi)
construct. Whereas most GFP-RNAi-transformed WT lines
exhibited almost complete silencing of GFP expression in
the T1 generation, various levels of GFP expression remained
among the GFP-RNAi-transformed rdr6-11 lines.
Homozygous expression of GFP-RNAi in the T3 generation
was not sufficient to induce complete GFP silencing in
several rdr6-11 lines. Our results indicate that RDR6 is
required for efficient hpRNA-induced RNA silencing in
plants. | en_US |
