Sorghum

Summary

An Australian patent, AU 743 706 B2, was granted to Pioneer Hi-Bred Inc. in January 2002 and a United States Patent, US 6 369 298 B1, was granted in April. The subject matter is the transformation of sorghum via Agrobacterium. A related application was filed in South Africa.

The granted Australian claims are more limited than the initially filed claims. The sorghum tissue to be transformed is now restricted to a certain group of tissues and the concentration of Agrobacterium cells in suspension is fixed. Another limiting factor of the granted invention is the number of copies of the sequence of interest inserted into the genome of a sorghum cell, tissue or plant, offering another avenue for designing around.

The method disclosed in the US patent utilizes an immature embryo as target for Agrobacterium. The gene cassette must contain a gene which confers resistance to a selection agent. Furthermore, during culture the medium must contain an antibiotic to eliminate the bacteria as well as contain the selection agent.

The broadest claim in the pending US application recites a sorghum plant transformed with Agrobacterium. The main restriction is that fewer than 5 copies of the introduced construct are present in the genome (multiple copies of integrated foreign DNA are generally undesirable).

Sorghum – Specific Patent Information

Patent Number Title, Independent Claims and Summary of Claims Assignee
AU 743706 B2

  • Earliest priority – 30 April 1997
  • Filed – 14 April 1998
  • Granted – 31 January 2002
  • Expected expiry – 13 April 2018
Title – Agrobacterium Mediated Transformation of Sorghum

Claim 1A method for transforming sorghum with a nucleotide sequence of interest, said method comprising the steps of:

A) contacting tissue selected from the group consisting of: an immature embryo or cells derived from an immature embryo, immature inflorescence, the basal portion of young leaves and tissue capable of forming callus and/or secondary embryos from a sorghum plant with an Agrobacterium comprising a vector which comprises said nucleotide sequence, wherein said nucleotide sequence comprises at least an expression cassette comprising a gene which confers resistance to a selection agent;
B) co-cultivating the tissue with said Agrobacterium in a concentration from about 1 x 103 cfu/ml to about 1.5 x 1010 cfu/ml;
C) culturing the tissue in a medium comprising an antibiotic capable of inhibiting the growth of Agrobacterium and said selection agent;
D) regenerating transformed sorghum plants.

Claim 16
A method for transforming sorghum with a nucleotide sequence, said method comprising the steps of:A) contacting a tissue selected from the group consisting of: an immature embryo or cells derived from an immature embryo, immature inflorescence, the basal portion of young leaves and tissue capable of forming callus and/or secondary embryos from a sorghum plant with an Agrobacterium comprising a super-binary vector which comprises said nucleotide sequence, wherein said nucleotide sequence comprises at least an expression cassette co mprising a gene which confers resistance to a selection agent;
B) co-cultivating the tissue with said Agrobacterium in a concentration from about 1 x 103 cfu/ml to about 1.5 x 1010 cfu/ml;
C) culturing the tissue in a medium comprising an antibiotic capable of inhibiting the growth of Agrobacterium and said selection agent;
D) regenerating transformed sorghum plants.
Claim 31Agrobacterium-mediated transformed sorghum plant, said plant comprising fewer than 5 copies of a nucleic acid of interest flanked by at least one T-DNA border sequence incorporated in its genome, wherein said plant is derived from tissue selected from the group consisting of: an immature embryo or cells derived from an immature embryo, immature inflorescence, the basal portion of young leaves and tissue capable of forming callus and/or secondary embryos.
Claim 41Agrobacterium-mediated transformed plant cell, said cell comprising fewer than 5 copies of a nucleic acid of interest flanked by at least one T-DNA border sequence incorporated in its genome, wherein said plant cell is sorghum and wherein said plant cell is derived from tissue selected from the group consisting of: an immature embryo or cells derived from an immature embryo, immature inflorescence, the basal portion of young leaves and tissue capable of forming callus and/or secondary embryos.
Claim 44Agrobacterium-mediated transformed plant tissue, said tissue comprising fewer than 5 copies of a nucleic acid of interest flanked by at least one T-DNA border sequence incorporated in its genome of cells of said tissue, wherein said plant is sorghum and wherein said plant tissue is derived from tissue selected from the group consisting of: an immature embryo or cells derived from an immature embryo, immature inflorescence, the basal portion of young leaves and tissue capable of forming callus and/or secondary embryos.

Method for sorghum transformation with Agrobacterium containing a gene that confers resistance to a selective agent. The tissue to be transformed is selected from: immature embryo, immature inflorescence, basal portion of young leaves and tissue capable of forming callus or secondary embryos. Agrobacterium contains a vector or a super binary vector having the mentioned gene. The transformed sorghum tissue or cell has less than 5 copies of the gene of interest flanked by at least one T-border.

Pioneer Hi-Bred Inc.

US 6369298

  • Earliest priority – 30 April 1997
  • Filed – 7 April 1998
  • Granted – 9 April 2002
  • Expected expiry – 6 April 2018
Title – Agrobacterium Mediated Transformation of Sorghum

Claim 1A method for transforming sorghum with a nucleotide sequence of interest, said method comprising the steps of: contacting an immature embryo from a sorghum plant with an Agrobacterium comprising a vector which comprises said nucleotide sequence, wherein said nucleotide sequence comprises at least an expression cassette comprising a gene which confers resistance to a selection agent; co-cultivating said immature embryo with said Agrobacterium; culturing said immature embryo in a medium comprising an antibiotic capable of inhibiting the growth of said Agrobacterium and said selection agent; regenerating transformed sorghum plants.
Claim 15A method for transforming sorghum with a nucleotide sequence, said method comprising the steps of: contacting an immature embryo from a sorghum plant with an Agrobacterium comprising a super-binary vector which comprises said nucleotide sequence, wherein said nucleotide sequence comprises at least an expression cassette comprising a gene which confers resistance to a selection agent; co-cultivating said immature embryo with said Agrobacterium; culturing said immature embryo in a medium comprising an antibiotic capable of inhibiting the growth of said Agrobacterium and said selection agent; regenerating transformed sorghum plants.

A method for transformation of sorghum in which an immature embryo is the target tissue for Agrobacterium. The gene cassette must contain a gene which confers resistance to a selection agent. During further culture the medium must contain an antibiotic to eliminate the bacteria as well as contain the selection agent.

US 2002/0138879 A1

  • Earliest priority – 30 April 1997
  • Filed – 19 March 2002
  • Application pending
Title – Agrobacterium Mediated Transformation of Sorghum

Claim 1An Agrobacterium-transformed sorghum plant wherein said plant comprises fewer than 5 copies of a nucleic acid of interest flanked by at least one T-DNA border sequence incorporated in its genome.
Claim 12A sorghum plant transformed by contacting an immature embryo from a sorghum plant with an Agrobacterium comprising a nucleic acid of interest; co-cultivating said immature embryo with said Agrobacterium; culturing said immature embryo in a medium comprising an antibiotic capable of inhibiting the growth of said Agrobacterium; and regenerating a transformed sorghum plant, said plant comprising fewer than 5 copies of said nucleic acid flanked by at least one T-DNA border sequence incorporated in its genome.
Claim 19A sorghum plant transformed by contacting an immature embryo from a sorghum plant with an Agrobacterium comprising a vector which comprises; a nucleic acid comprising at least one expression cassette comprising a gene of interest; and a nucleic acid comprising at least one expression cassette comprising a gene which confers resistance to a selection agent; co-cultivating said immature embryo with said Agrobacterium; culturing said immature embryo in a medium comprising an antibiotic capable of inhibiting the growth of said Agrobacterium and a selection agent; and regenerating a transformed sorghum plant, said plant comprising fewer than 5 copies of said vector flanked by at least one T-DNA border sequence incorporated in its genome.

This application is a division of now granted US 6369298.

A sorghum plant transformed with Agrobacterium with fewer than 5 copies of the introduced construct integrated in the genome.

Remarks National phase entry of WO 98/49332 has been accepted in South Africa (ZA 98/03603).

Note: Patent information on this page was last updated on 8 February 2006.