A MAIZE ENDOSPERM-SPECIFIC PROMOTER CAN BE USED AS A GENERAL-PURPOSE PROMOTER FOR HIGH-LEVEL GENE-EXPRESSION IN PLANTS

Transient beta-glucuronidase (GUS) expression was utilized to test the strength of a novel promoter system based on the maize (Zed mays) end osperm-specific b-32 gene promoter and its physiological activator Opa que-2 (O2). Up to ten O2 binding sites were taken together in the same promoter either separately, or in combination with the CaMV (Cauliflo wer 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 pre sented indicate that b-32 promoter, driven by the Opaque-2 protein, mi ght be a good choice for gene expression in plants.