Callus Transformation

Callus Transformation – patents and application assigned to Japan Tobacco

Patents and application assigned to Japan Tobacco

In the disclosures, an explant of a monocot in the process of dedifferentiation or already dedifferentiated is used for transformation with Agrobacterium. A dedifferentiated tissue or a tissue in the process of dedifferentiation is described in the disclosures as an explant cultured on a dedifferentiation medium for not less than 7 days. Among the preferred tissues are a callus, an adventitious embryo-like tissue, and suspension cells.

Specific patent information

Patent Number Title, Independent Claims and Summary of Claims Assignee
US 5591616 A

  • Earliest priority – 7 July 1992
  • Filed – 3 May 1994
  • Granted – 7 January 1997
  • Expected expiry – 6 July 2013
Title – Method of transforming monocotyledons

Claim 1
A method for transforming a monocotyledon callus, comprising contacting a cultured tissue of a monocotyledon during dedifferentiation wherein said dedifferentiation is obtained by culturing an explant on a dedifferentiation-inducing medium for not less than 7 days or a dedifferentiated cultured tissue of a monocotyledon, with a bacterium belonging to the genus Agrobacterium containing a desired gene.
Claim 17
A method for transforming a monocotyledon with a desired gene, comprising: contacting a cultured tissue of said monocotyledon during dedifferentiation thereof, or a dedifferentiated cultured tissue of said monocotyledon, with a suspension of Agrobacterium tumefaciens having a cell population of 106 to 1011 cells/ml for 3-10 minutes and then culturing said cultured tissue of said monocotyledon during dedifferentiation thereof, or said dedifferentiated cultured tissue of said monocotyledon, on a solid medium for several days together with said Agrobacterium tumefaciens, or adding said Agrobacterium tumefaciens to culture medium in which said cultured tissue of said monocotyledon during dedifferentiation thereof or said dedifferentiated cultured tissue of said monocotyledon is cultured, and continuously culturing said cultured tissue of said monocotyledon during dedifferentiation or said dedifferentiated cultured tissue of said monocotyledon together with said Agrobacterium tumefaciens, wherein said dedifferentiated cultured tissue of said monocotyledon is selected from the group consisting of a tissue cultured during the process of callus formation which is cultured for not less than 7 days after an explant is placed on a dedifferentiation-inducing medium and a callus, and wherein said Agrobacterium tumefaciens contains plasmid pTOK162, and said desired gene is present between border sequences of the T region of said plasmid pTOK162, or wherein said desired gene is present in another plasmid contained in said Agrobacterium tumefaciens.

US 5591616 claims:

  • a method for transforming monocotyledon callus by contacting dedifferentiating tissue of not less than 7 days of culture or dedifferentiated tissue with Agrobacterium having a desired gene; and
  • a method of transforming such tissue or transforming a callus by contacting the tissue/callus with a suspension of Agrobacterium cells of 106 – 1011 cells/ml for 3-10 minutes. The bacterium contains the desired gene either between the T- borders of the plasmid pTOK162 or in another plasmid.

Japan Tobacco

EP 604662 A1

  • Earliest priority – 7 July 1992
  • Filed – 6 July 1994
  • Application pending
Title – Method of transforming monocotyledon

Claim 1
A method for transforming a monocotyledon comprising transforming a cultured tissue during dedifferentiation process or a dedifferentiated cultured tissue of said monocotyledon with a bacterium belonging to genus Agrobacterium containing a desired gene.

The claims submitted in the European application EP 604662 A1 are the same as the claims of the Australian patent, below.

AU 667939 B

  • Earliest priority – 7 July 1992
  • Filed – 6 July 1993
  • Granted – 18 April 1996
  • Expected expiry- 6 July 2013
Title – Method of transforming monocotyledon

Claim 1
A method for transforming a monocotyledon comprising transforming a cultured tissue during dedifferentiation process or a dedifferentiated cultured tissue of said monocotyledon with a bacterium belonging to genus Agrobacterium containing a desired gene.

The lead claim in the Australian patent AU 667 939 is broader than in the United States patent. In the Australian patent, a dedifferentiating or dedifferentiated tissue of a monocot is also used as the initial tissue for transformation, but there is no restriction on the number of days of culture in the medium to induce dedifferentiation.

US 2002/178463 A1

  • Earliest priority – 7 July 1992
  • Filed – 13 January 1999
  • Application pending
Title – Method for transforming monocotyledons

Claim 1
A method for transforming a monocotyledon, comprising contacting a cultured tissue of said monocotyledon during dedifferentiation thereof obtained by culturing an explant on a dedifferentiation-inducing medium for less than 7 days with a bacterium belonging to the genus Agrobacterium containing a super binary vector having the virulence region of Ti plasmid pTiBo542 contained in Agrobacterium tumefaciensA281, left and right border sequences of T-DNA of a Ti plasmid or an Ri plasmid of a bacterium belonging to the genus Agrobacterium, and a desired gene located between said left and right border sequences.
Claim 13
A method for transforming a monocotyledon, comprising contacting a cultured tissue of said monocotyledon during dedifferentiation thereof obtained by culturing an explant derived from an immature tissue on a dedifferentiation-inducing medium for less than 7 days with a bacterium belonging to the genus Agrobacterium containing a desired gene and containing a vector having the virulence region of Ti plasmid contained in Agrobacterium tumefaciens.

This application is a continuation of abandoned US 08/668464, which was a continuation of now granted US 5591616.

Claims in this applicaiton recite Agrobacterium-mediated transformation of monocotyledon explants, where the explant is cultured on dedifferentiation medium for less than 7 days, then infected with Agrobacterium containing a vector that has the virulence region (in particular a vector that contains the virulence region of Ti plasmid pTiBo542 from A. tumefaciens A281 in the case of claim 1).

Remarks
  1. National phase entry of WO 1994/00977 in Canada (CA 2121545) is pending.
  2. National phase entry of WO 1994/00977 in Japan (JP 2649287 B2) has been published as granted on 3 September 1997.

Note: Patent information on this page was last updated on 21 February 2006.