Abstract
The polyadenylation signal of a pea ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (rbcS) gene has been studied using in vitro mutagenesis and Ti plasmid-mediated transformation of tobacco. Analysis of a mutant that is lacking sequences upstream from −6 (relative to the "normal" site of polyadenylation of RNAs from the rbcS-E9 gene) reveals a number of alternate polyadenylation sites located downstream from the normal poly(A) site. Transcripts carrying these sequences end at any one of at least seven sites between 20 and 300 bases downstream from the normal site. These sites are seen in populations of transgenic plant cells, and also in independent transgenic plants.