Super-promoter:TEV, a powerful gene expression system for tobacco hairy roots.

In order to identify a promoter system for high-level expression of transgenes in hairy roots, we characterized the chimeric super-promoter fused to the translational enhancer from tobacco etch virus (TEV). Transgenic tobacco plants and hairy roots were generated with the super-promoter:TEV sequence and a modified green fluorescence protein (mGFP5) as a reporter gene. To exploit the utility of hairy root cultures as a secretion-based expression system, the signal peptide of patatin was fused to mGFP5 to direct its secretion into the culture medium.

Self-excision of the antibiotic resistance gene nptII using a heat inducible Cre-loxP system from transgenic potato.

Resistance to antibiotics mediated by selectable marker genes remains a powerful selection tool for transgenic event production. However, regulatory agencies and consumer concerns favor these to be eliminated from food crops. Several excision systems exist but none have been optimized or shown to be functional for clonally propagated crops.