LOCALIZATION OF CIS ELEMENTS IN THE PROMOTER OF A WHEAT ALPHA-AMY2 GENE

A functional analysis of the promoter from the wheat alpha-amylase gene alpha-Amy2/54 is described. Mutant alpha-Amy2/54 promoters containing replacements or deletions were constructed and their ability to direct expression of the reporter gene beta-glucuronidase (GUS) in gibberellin-responsive oat aleurone protoplasts analysed. Chimaeric promoters using regions of the cauliflower mosaic virus (CaMV) 35S and alpha-Amy2/54 promoters were also analysed. The results suggest that at least three regions within the alpha-Amy2/54 promoter contain cis elements that are necessary for high-level gibberellin-regulated transcription. Fusion of 1.8 kb of promoter sequence upstream from -117 bp to a minimal (-55 CaMV 35S) promoter gave rise to hormone-independent expression implying that the region 3' to -117 bp contains an element which represses transcription in the absence of gibberellin or presence of abscisic acid.