A maize endosperm-specific promoter can be used as a general purpose promoter for high level gene expression in plants

Transient β-glucuronidase (GUS) expression was utilized to test the strength of a novel promoter system based on the maize (Zea mays) endosperm- specific b-32 gene promoter and its physiological activation Opaque 2 (O2). Up to ten O2 binding sites were taken together in the same promoter either separately, or in combination with the CaMV (Cauliflower Mosaic Virus) 35S promoter. The efficiency of the double component system has been tested versus a construct bearing the CaMV promoter coupled with GUS gene, in which the sequences surrounding the ATG were modified to fit an optimal translation start for eukaryotes. Data presented indicate that b-32 promoter, driven by the Opaque-2 protein, might be a good choice for gene expression in plants.