EP 242246 B1

This patent protects plant cells containing DNA that provides resistance to PPT and its products, while at the same time protecting the process that inactivates the GS inhibitor, namely Bialaphos or PPT.

EP 242246 B1
Title Plant cells resistant to glutamine synthetase inhibitors, made by genetic engineering
Issue Date 11 Nov 1992
Assignees Plant Genetic Systems NV and Biogen NV
Inventors Leemans J, Botterman J, de Block M, Thompson C, Mouva R
Appl No and Filing Date EP 87/400544 11 Mar 1987
Priority EP 86/400521 11-03-1986; EP 87/400141 21-011987
Abstract The invention relates to a DNA fragment containing a determined gene, the expression of which inhibits the antibiotic and herbicidal effects of Bialaphos and related products. It also relates to recombinant vectors, containing such DNA fragment, which enable this protective gene to be introduced and expressed into cells and plant cells.

Independent claim 1 protects a bar gene, either partially or in its entirety, that is isolated from Streptomyces hygroscopicus and encodes an active enzyme. It is inferred by the construction of the following dependent claims that such a nucleotide sequence would include various codon combinations yielding the same peptide sequence. The claims therefore encompass codon degeneracy. The peptide sequence corresponds to a bar gene isolated from a specific S. hygroscopicus strain.

Claims 4 and 5 recite a process to produce a transgenic plant resistant to a glutamine synthetase inhibitor by introducing a gene encoding a phosphinothricin acetyl transferase. The breadth of the claims is restricted by their dependence on Claims 1 and 2. Thus, the processes claimed in Claims 4 and 5 are limited to the transformation of plant tissue with the specific nucleotide sequence in Claim 1 (i.e. the bar gene) that codes for a protein having phosphinotricinacetyl transferase activity from S. hygroscopicus.

Similarly to EP 242236, Claims 19 and 23 recite the processes of using the gene construct described above for weed and fungal control.