Patent granted to Nunhems Zaden BV

The present United States patent granted to Nunhems Zaden from Holland discloses a process to obtain transgenic plants by using Agrobacterium mutants deficient in the biosynthesis of specified vital biomolecules. This allows a controlled systemic infection of the tissues to be transformed to be maintained for longer periods, thereby increasing the probability of successful infection. The Agrobacterium can then be eliminated by omission of those nutrients from the incubation medium.

Specific Patent Information

Patent Number Title, Independent Claims and Summary of Claims Assignee
US 6323396 B1

  • Earliest priority – 25 August 1997
  • Filed – 24 February 2000
  • Granted – 27 November 2001
  • Expected expiry – 23 February 2020
Title – Agrobacterium-mediated transformation of plants

Claim 1
A process to produce a dicotyledonous transgenic plant, said plant comprising

  • a foreign DNA fragment integrated into the genome of at least some of its cells, said process comprising the following steps:

1) providing a plant which is systemically infected with an Agrobacterium strain auxotrophic for methionine or cysteine, or adenine and histidine, harboring a DNA of interest which is operably linked to at least one T-DNA border sequence; and
2) generating a transgenic plant from a single cell or a group of cells isolated from said systemically infected plant.

Claim 11
Bacterial strain LBA4404metHV, deposited as LMG P-18486.
Claim 12
Bacterial strain ATHV ade,his, deposited as LMG P-18485.
Claim 13
A method for producing a transgenic plant, said plant comprising

  • a foreign DNA fragment integrated into the genome of at least some of its cells, said process comprising:

a. cocultivating a plant cell, plant tissue, explant or plant with an Agrobacterium strain auxotrophic for methionine or cysteine, or for adenine and histidine, to generate a transgenic cell; and
b. regenerating a transgenic plant from said transgenic cell.

The United States patent US 6323396 B1 claims

  • A process for the production of transgenic plants (Claims 1 and 13) utilizing an Agrobacterium strain deficient in the biosynthesis of one of the following:
    • methionine
    • cysteine
    • adenosine and histidine
  • Co-cultivating a plant or plant tissue with one of the auxotrophic Agrobacterium mutants described above carrying a desired foreign DNA and regenerating a transgenic plant from such a treated tissue (Claim 13).
  • Systemically infecting a plant with one of the auxotrophic Agrobacterium mutants described above carrying a desired foreign DNA and regenerating a transgenic plant from such a treated tissue (Claim 1).
  • Two auxotrophic Agrobacterium strains as described (Claims 11 and 12).
Nunhems Zadens B.V.
AU 736349 B2

  • Earliest priority – 25 August 1997
  • Filed – 25 August 1998
  • Granted – 26 July 2001
  • Expected expiry – 24 August 2018
Title – Improved Agrobacterium-mediated transformation of plants

Claim 1
A process to produce a transgenic plant comprising

  • a foreign DNA fragment integrated into the genome of at least some of its cells, said process comprising the following steps:

1) providing a plant which is systemically infected with an auxotrophic Agrobacterium strains harbouring a DNA of interest which is operably linked to at least one T-DNA border sequence; and
2) generating a transgenic plant from a single cell or a group of cells isolated from said systemically infected plant.

Claim 12
Bacterial strain LBA4404met.
Claim 13
Bacterial strain ATHVadehis.
Claim 14
The use of an Agrobacterium strain auxotrophic for methionine or cysteine or for adenine and histidine in Agrobacterium-mediated transformation of plants.
Claim 15
The use of Agrobacterium strain auxotrophic for methionine or cysteine or for adenine and histidine in Agrobacterium mediated transformation of callus from sugarbeet.
Claim 16
The use of Agrobacterium strain auxotrophic for methionine or cysteine or for adenine and histidine in Agrobacterium mediated transformation of corn protoplasts.

Claim 1 in granted AU 736349 does not have a limit to the type of nutrient (or nutrients) the Agrobacterium strain is auxotrophic for.

“Systemically infected plant” is defined in the specification as ‘a plant wherein  the Agrobacterium strains is present in at least some part of the plant‘.

EP 1009844 B1

  • Earliest priority – 25 August 1997
  • Filed – 25 August 1998
  • Granted – 16 June 2004
  • Expected expiry – 24 August 2018
Title – Improved Agrobacterium-mediated transformation of plants

Claim 1
A process to produce a transgenic plant comprising

  • a foreign DNA fragment integrated into the genome of at least some of its cells, said process comprising the following steps:

1) providing a plant which is systemically infected with an auxotrophic Agrobacterium strain harbouring a DNA of interest which is operably linked to at least one T-DNA border sequence; and
2) generating a transgenic plant from a single cell or a group of cells isolated from said systemically infected plant.

Claim 12
Bacterial strain LBA4404metHV, deposited as BCCM/LMG P-18486.
Claim 13
Bacterial strain ATHV ade,his, deposited as BCCM/LMG P-18485.
Claim 14
The use of an Agrobacterium strain auxotrophic for methionine or cysteine, or for adenine and histidine, in Agrobacterium-mediated transformation of plants.
Claim 15
The use of an Agrobacterium strain auxotrophic for methionine or cysteine, or for adenine and histidine, in Agrobacterium mediated transformation of callus from sugarbeet.
Claim 16
The use of an Agrobacterium strain auxotrophic for methionine or cysteine, or for adenine and histidine, in Agrobacterium mediated transformation of corn protoplasts.

Designated contracting States at the time of grant are: Austria (patent lapsed as reported by INPADOC), Belgium (patent lapsed as reported by EPO), Switzerland (patent lapsed as reported by INPADOC), Cyprus, Germany (patent lapsed as reported by EPO), Denmark (patent lapsed as reported by EPO), Spain (patent lapsed as reported by EPO), Finland (patent lapsed as reported by EPO), France (patent lapsed as reported by EPO), United Kingdom (patent lapsed as reported by INPADOC), Greece (patent lapsed as reported by EPO), Ireland (patent lapsed as reported by INPADOC), Italy, Liechtenstein (patent lapsed as reported by INPADOC), Luxembourg, Monaco (patent lapsed as reported by EPO), Netherlands (patent lapsed as reported by INPADOC), Portugal, Sweden (patent lapsed as reported by INPADOC)

Granted EP 1009844 recites the same method of Agrobacterium-mediated transformation as that of AU 736349.

WO 1999/010512 A1

  • Earliest priority – 25 August 1997
  • Filed – 25 August 1998
  • OPI – 4 March 1999
  • Predicted expiry – N/A
Title – Improved Agrobacterium-mediated transformation of plants

Claim 1

A process to produce a transgenic piant comprising a foreign DNA fragment integrated into the genome of at least some of its cells, said process comprising the following steps:
1) providing a plant which is systemically infected with an auxotrophic Agrobacterium strain harbouring a DNA of interest which is operably linked to at least one T-DNA border sequence; and
2) generating a transgenic plant from a single cell or a group of cells isolated from said systemically infected plant.

Claim 12

Bacterial strain LBA44O4met.

Claim 13

Bacterial strain ATHVadehis.

Claim 14

The use of an Agrobacterium strain auxotrophic for methionine or cysteine or for adenine and histidine in Agrobacterium-mediated transformation of plants.

Claim 15
The use of Agrobacterium strain auxotrophic for methionine or cysteine or for adenine and histidine in Agrobacterium mediated transformation of calius from sugarbeet.
Claim 16
The use of Agrobacterium strain auxotrophic for methionine or cysteine or for adenine and histidine in Agrobacterium mediated transformation of corn protoplasts.
Remarks
  1. National phase entry of WO 1999/010512 A1 in Canada (CA 2301707) is pending.
  2. National phase entry of WO 1999/010512 A1 in China (CN 1188525) has been granted on 9 February 2005.
  3. National phase entry of WO 1999/010512 A1 in Japan (JP 2001514009) is deemed to be withdrawn on 1 November 2005.

Note: Patent information on this page was last updated on 7 March 2006.