Fig. 1.

Structure of the Acc-2,1, Acc-2,2, and Acc-2,4 promoter–GUS fusions and relative transient expression of GUS in wheat protoplasts. Numbers identifying key features of the constructs correspond to nucleotide positions in cloned gene fragments (Supporting Materials and Methods). The approximate position of leader AUG codons is indicated by asterisks. These triplets were changed to non-AUG codons in constructs 2,1-A* and 2,2-A*. P2A and P2B, alternative promoters. 5′ terminal deletions are indicated by shortened black arrows, and internal deletions are marked with rectangles. The structure of the two transcript types (Acc-2A and Acc-2B) is illustrated for gene Acc-2,1. Both transcript types were identified for gene Acc-2,4 as well. Only the most upstream 5′ splice site found in transcript Acc-2,1B is shown. Other sites used for splicing of the intron in Acc-2 genes are located 23 and 30 nucleotides further downstream. Activity of construct 2,2-A was taken as 1.