Fig. 2.

A third 10-bp motif is required for suspensor transcription. a and b Suspensor GUS activity in transgenic tobacco embryos containing 54-bp GOF constructs with mutations within the 10-bp-related motif (a) or 10-bp motif (b). c A consensus 10-bp/10-bp-like/10-bp-related motif sequence was generated from DNA sequences shown to function as the 10-bp motif in transgenic tobacco embryos (Kawashima et al. 2009). Green arrows indicate the 10-bp-related motif. The sequences of the 10-bp and 10-bp-related motifs are shown in red and green fonts, respectively. Black crosses indicate mutations in these motifs. The mutation sequence is written in black, lower case, and underlined font. +++ in the Expression column indicates that suspensor GUS activity was strong and detected by 2-h incubation for a majority of the GUS-positive lines; −/+ in the Expression column indicates that suspensor GUS activity was weak and not detected by 2-h incubation in the majority of embryos from GUS-positive lines; − in the Expression column indicates no detectable suspensor GUS activity. Numbers in the Lines column indicate the number of individual transformants displaying suspensor GUS activity over the total number of individual transformants analyzed. Numbers in the Embryos column indicate the number of embryos displaying suspensor GUS activity by 24-h incubation over the total number of analyzed embryos of GUS-positive lines. Photographs were taken after 24-h GUS incubation (Scale bar: 50 μm)