Patent issues surrounding the bar gene

When using the bar gene, besides the gene itself, several IP protected materials and processes may be involved, such as processes for plant transformation, use of genetic regulatory elements, use of antibiotic resistance genes as selectable markers, etc. These topics are discussed in the technology landscapes “Agrobacterium-mediated plant transformation”, “Promoters”, and “Antibiotic Resistance”. In this landscape, we analyze patent issues around the bar gene as such.

In the case of the bar gene (not its uses) we are faced with a relatively simple intellectual property ownership situation. Essentially all key patents are held by Bayer Crop Science, although assignees listed on the patent documents include Plant Genetic Systems, Hoechst, AgrEvo and Aventis. To understand why the bar gene patent portfolio is now in the hands of Bayer Crop Science, a schematic overview of the corporate consolidation history which led to the creation of one of the major players in the agrichemicals business worldwide is included in the analysis.

The bar gene patents owned by Bayer Crop Science are divided into three main families. The first patent family is the dominant family and was originally assigned to Plant Genetic Systems (PGS) and Biogen NV. It claims the use of the bar gene in plants and plant products. More specifically, this patent family claims the use of the gene in creating herbicide resistant crops and also its use as a selectable marker.

The other two patent families in the Bayer portfolio (assigned originally to Hoechst AG) strengthen the corporate position on the bar gene by claiming additional bar genes from other organisms and uses, e.g. isolating the gene from gram-negative bacteria, the gene itself, its use as a selectable marker in bacteria, codon-optimized versions for expression in plant cells, and treatment of sewage contaminated with phosphinothricin.

Who owns the dominant patents on the bar gene?

Currently patents claiming the bar gene are mainly in the hands of Bayer Crop Science. The schematic representation below displays the corporate history of the bar gene patent portfolio. In all the bar gene patents discussed in this white paper the reader will find applicants (assignees) listed as Hoechst AG, Plant Genetic Systems NV, AgrEvo (Hoechst Schering GmbH), and Aventis (Crop Science GmbH); these company names appear in color in the graphic. For clarity, mergers, demergers, takeovers and spin-offs not related to the carryover of the portfolio relevant to this discussion have not been included in the graphic.

The acquisition of the Belgian company Plant Genetic Systems (PGS) by AgrEvo in 1996 was an important strategic move to gain access to a broad portfolio of traits and enabling technologies required to participate in the highly competitive market of genetically engineered crops. At the time AgrEvo had fallen behind Monsanto and Novartis (now Syngenta) in securing a competitive market position in the area of genetically modified insect and herbicide resistant crops. With the acquisition of PGS, AgrEvo took a serious step to enter the U.S. and the Canadian markets for transgenic crops, two of the largest markets in world. Companies are still preparing for a definitive opening of the European markets for genetically modified crops, a development stalled by public perception.

With the acquisition of PGS, AgrEvo gained access to various technologies of PGS in its patent portfolio, such as gene promoters, marker genes, techniques to insert specific genes into plant cells, and gene expression technology to optimise the efficacy of expression of foreign genes in plants. Additionally, PGS had engaged in research and development of novel technologies, particularly in the area of functional genomics, but also in engineering disease tolerant plants and modifying certain quality traits. PGS’s products included corn, oilseed rape (canola) and selected vegetables engineered for insect protection (based on the expression of Bt toxin), herbicide tolerance and pollination control.

PGS’s herbicide tolerance technology was developed in collaboration with AgrEvo, based on tolerance to AgrEvo’s herbicide LibertyTM (glufosinate) by virtue of the bar gene. PGS’s SeedLinkTM pollination control technology is also based on tolerance to LibertyTM.

After the merger of AgrEvo and Rhône-Poulenc, which gave rise to Aventis, the agricultural section of this merger was called Aventis Crop Science. The Hoechst conglomerate, holder of Aventis and other companies, finally decided to shed its agrichemicals section by selling to Bayer AG, which recently gave rise to Bayer Crop Science, explaining thereby the migration of the bar gene portfolio over time.