Gene constructs used to analyze dsRNA effects. In
p35S∷A-GUS-S, gene-specific sequences (open boxes with arrows
indicating the orientation) in the antisense (A) and sense (S)
orientations were linked with a 1,022-bp fragment of the GUS gene
(hatched box) and controlled by the 35S promoter (solid arrow). A
schematic structure of the predicted dsRNA stem with a single-stranded
loop generated by p35S∷A-GUS-S constructs is shown. In
p35S∷A-NOS∷S, gene-specific sequences in the antisense and
sense orientations were controlled by the 35S promoter and the nopaline
synthase promoter, respectively (open arrow). p35S∷A contains
gene-specific sequences in the antisense orientation under control of
the 35S promoter. pNOS∷S contains gene-specific sequences in the
sense orientation driven by the nopaline synthase promoter. Solid box,
the 3′ end of nopaline synthase.