Figure 5.

RY Motifs Are Necessary for the High Expression of SOM.

(A) Seed-specific expression driven by a 2-kb region of the SOM promoter. SOM_pro:GUS indicates various tissues and organs of transgenic plants harboring SOM_pro:GUS, while 35S_pro:GUS indicates transgenic plants harboring 35S_pro:GUS. Numbers and DS on figures indicate DPA and dry seeds, respectively. Bar = 5 mm.

(B) Immunoblot analysis showing the increased expression of SOM-GFP protein by the SOM promoter during seed maturation and imbibition. hours, hours after imbibition.

(C) Decreased expression of GUS reporter transcripts (GUS/PP2A) by the SOM promoter with mutations in their RY motifs. Numbers indicate average ± sd (n = 10). Seeds imbibed for 24 h under phyB_off condition were used for analysis. The inset shows the light-dependent expression of the GUS transcript in two transgenic lines. Error bars are sd (n = 3).

(D) Decreased expression of SOM mRNA (SOM/PP2A) in the som-4 allele. Seeds imbibed for 12 h were used for analysis. Triangles indicate RY motifs in the SOM promoter (sd, n = 3).