Increase of foreign gene expression in monocot and dicot cells by an intron in the 5' untranslated region of a soybean phosphoenolpyruvate carboxylase gene.

A genomic clone containing part of the coding region and upstream sequences of a phosphoenolpyruvate carboxylase (PEPC) gene was isolated from a soybean genomic library. The first intron of this gene is located in the 5' untranslated region. This intron-spanning fragment is capable of increasing GUS activity in plant cells.