Sugarbeet modified for herbicide and fungus resistance

Sugarbeets were modified to constitutively express phosphinothricin acetyltransferase (pat) gene. As a result of the genetic modification the resulting sugarbeet is tolerant to L-phosphinothricin-containing herbicides.

Furthermore, the plants were also modified to constitutively express the defensin-like protein 1 gene (AMP1) of Dahlia merckii. Defensins have antimicrobial properties, therefore the introduction of the AMP1 gene confers a resistance to pathogenic fungi to the plants.

pIG35SDM

The pIG35SDM plasmid was transferred into the plants as naked DNA via protoplast transformation. As a result, some of the transformation events have the entire transformation vector integrated into their genome while others only contain parts thereof.

In addition to the genetic elements listed above, the pIG35SDM plasmid also contained the following sequences which were also transferred into the modified sugarbeet but are non-functional in plants:

* The imidazoleglycerol phosphate dehydratase (his3) gene from Saccharomyces cerevisiae which is expressed as a selection marker in bacteria under the control of its native promoter and terminator sequences. Furthermore, due to the close proximity of these genes within the yeast genome, the transcription initiation site of the yeast ATP-dependent RNA helicase (ded1) gene and the first 6 bp of the ded1 coding sequence are included with of the 3' sequence of the his3 gene.

* Portions of the Lac operon from Escherichia coli, specifically: a 12 bp sequence of the N terminus of the lacZ  gene, the promoter/operator region of the lacZ gene and 88 bp of the sequence of the C terminus of the lacI gene.

* The origin of replication of the  pMB1 plasmid from E. coli.

Each of the transformation events contain up to three copies of the genes integrated into their respective genomes. There is no extrachromosomal replication of the genetic material.