General transformation methods
A patent with broad claims to transformation of dicots in general with a non-oncogenic Agrobacterium was issued to Washington University.
Although issued in 2000 in the United States, this patent has an initial priority date of 1983. Thus, the prosecution process took approximately 17 years until the patent was finally granted by the United States Patent and Trademark Office (USPTO). The patent could be considered one of the broadest in scope granted in the area of Agrobacterium transformation. The patent rights under this patent may overlap with the rights already granted in previous patents related to transformation of dicots with Agrobacterium.
One of the distinctive factors of that patent is the knocking out of the cytokinin function in the Ti plasmid in order to get a non-tumorigenic Agrobacterium strain. As a general practice in Agrobacterium-mediated transformation, “disarmed” strains lacking functional tumorigenic genes are used. The present patent thus may constitute a blow for a widely used and standard procedure carried out to regenerate complete transformed dicot plants.
With respect to enablement of the invention, the examples referred to transformation of tobacco only, a model plant at the time the invention was initially filed and one of the easiest dicot plants to be transformed with Agrobacterium. No other plant examples are provided in the disclosure.
Most other patents analyzed here claim transformation of dicots in conjunction with the use of co-integrated or binary vectors, the vectors being the main subject matter of the claimed inventions. This group of patents are reviewed under the section of “Binary vectors and co-integrated vectors”. In the following table, you will find a reference to those patents and links to more information on them.
|Assigned to||Patent No.||Title|
|Washington University||US 6051757||Regeneration of plants containing genetically engineered T-DNA|
|Schilperoort & Hille||US 4693976||Process for the incorporation of foreign DNA into the genome of dicotyledonous plants using stable co-integrated plasmids.|
|EP 120515 B1||A process for the incorporation of foreign DNA into the genome of dicotyledonous plants; a process for the production of Agrobacterium tumefaciens bacteria.|
|Syngenta Mogen B.V.||US 4940838||Process for the incorporation of foreign DNA into the genome of dicotyledonous plants.|
|EP 120516 B1||A process for the incorporation of foreign DNA into the genome of dicotyledonous plants; Agrobacterium tumefaciens bacteria and a process for the production thereof.|
|Leiden University & Schilperoort||US 5149645||A process for introducing foreign DNA into the genome of plants|