Abstract
Most effort in expression vector development has been devoted to the identification and characterization of highly expressed and/or regulated promoter. Another important parameter of gene expression is 3'-processing and polyadenylation of pre-mRNA. Most eukaryotic mRNAs are cleaved post-transcriptionally at a specific sites downstream of polyadenylation signal in the 3'-untranslated region. Functional polyadenylation signals are required for efficient transcription termination. Furthermore, the strength of the poly(A) signal correlates with termination efficiency. Previous studies showed that terminators strongly affect the level of gene expression. We isolate the efficient transcription terminator contribute to express a foreign gene in plants more effectively. The terminator of the heat shock protein gene increases the mRNA level approximately 2-fold more than the nopaline synthase (NOS) terminator. When combined with the HSP terminator, a translational enhancer increased gene expression levels approximately 60- to 100-fold in transgenic plants.
