Methods of modulating seed and organ size in plants

1. A method of increasing organ size and/or seed size in a plant comprising:

expressing a nucleic acid encoding a DA1 protein within cells of said plant, wherein the DA1 protein comprises an amino acid sequence having at least 90% sequence identity to one or more of SEQ ID NOs: 4 to 27, wherein the amino acid sequence of the DA1 protein comprises one or more sequence alterations relative to the wild-type LIM-like domain of SEQ ID NO: 28 that disrupt or inactivate the LIM-like domain of the DA1 protein, wherein the wild-type LIM-like domain comprises two Zn finger motifs and the one or more sequence alterations abolish one or both Zn finger motifs, and wherein the plant has increased organ size and/or seed size compared to a plant without the one or more sequence alterations.

2. The method according to claim 1 wherein the DA1 protein is expressed from a heterologous nucleic acid coding sequence in one or more cells of the plant.

3. A method of producing a plant with an increased organ size and/or seed size comprising:

introducing into a plant cell a heterologous nucleic acid which encodes a DA1 protein, wherein the amino acid sequence of the DA1 protein comprises one or more sequence alterations relative to the wild-type LIM-like domain of SEQ ID NO: 28 that disrupt or inactivate the LIM-like domain of the DA1 protein, or

introducing a mutation into the nucleotide sequence of a plant cell which encodes a DA1 protein, wherein the mutation encodes one or more sequence alterations relative to the wild-type LIM-like domain of SEQ ID NO: 28 that disrupt or inactivate the LIM-like domain of the DA1 protein, and

regenerating the plant from the plant cell, wherein the plant has increased organ size and/or seed size compared to a plant without the heterologous nucleic acid or the mutation, wherein the DA1 protein comprises an amino acid sequence having at least 90% sequence identity to one or more of SEQ ID NOs: 4 to 27, and wherein the wild-type LIM-like domain comprises two Zn finger motifs and the one or more sequence alterations abolish one or both Zn finger motifs.

4. The method according to claim 1 wherein the DA1 protein with the inactivated LIM-like domain has increased peptidase activity relative to the wild-type DA1 protein.

5. The method according to claim 1 wherein the wild-type LIM-like domain has the sequence of SEQ ID NO: 28, 29, 30 or 31.

6. The method according to claim 1 wherein the DA1 protein further comprises a C terminal region having at least 90% sequence identity to residues 198 to 504 of SEQ ID NO: 4, residues 180 to 487 of SEQ ID NO: 5, residues 212 to 514 of SEQ ID NO: 6, residues 229 to 532 of SEQ ID NO: 7, residues 229 to 532 of SEQ ID NO: 8, residues 174 to 478 of SEQ ID NO: 9, residues 174 to 474 of SEQ ID NO: 10, residues 178 to 478 of SEQ ID NO: 11, residues 176 to 462 of SEQ ID NO: 12, residues 179 to 482 of SEQ ID NO: 13, residues 182 to 486 of SEQ ID NO: 14, residues 573 to 878 of SEQ ID NO: 15, residues 181 to 486 of SEQ ID NO: 16, residues 207 to 512 of SEQ ID NO: 17, residues 189 to 491 of SEQ ID NO: 18, residues 181 to 486 of SEQ ID NO: 19, residues 204 to 508 of SEQ ID NO: 20, residues 247 to 553 of SEQ ID NO: 21, residues 219 to 528 of SEQ ID NO: 22, residues 1296 to 1613 of SEQ ID NO: 23, residues 128 to 450 of SEQ ID NO: 24, residues 404 to 702 of SEQ ID NO: 25, residues 343 to 644 of SEQ ID NO: 26, or residues 256 to 587 of SEQ ID NO: 27.

7. The method according to claim 6 wherein the C terminal region further comprises the metallopeptidase motif HEMMH (SEQ ID NO: 32).

8. The method according to claim 7 wherein the C terminal region further comprises the amino acid sequence EK(X) 8 R(X) 4 SEEQ (SEQ ID NO: 33) or EK(X) 8 R(X) 4 SEQ (SEQ ID NO: 34), wherein X is any amino acid.

9. The method according to claim 1 wherein the DA1 protein further comprises a UIM1 domain of SEQ ID NO: 35 and a UIM2 domain of SEQ ID NO: 36.

10. The method according to claim 1 wherein the nucleic acid encoding the DA1 protein is operably linked to a heterologous promoter.

11. The method according to claim 10 wherein the promoter is a tissue-specific promoter or an inducible promoter.

12. The method according to claim 10 wherein the nucleic acid encoding the DA1 protein is comprised in one or more vectors.

13. The method according to claim 1 further comprising selecting a plant or plant cell having increased organ size and/or seed size compared to control plants.

14. The method according to claim 1 further comprising sexually or asexually propagating or growing off-spring or descendants of the plant expressing the DA1 protein comprising the one or more sequence alterations.

15. The method according to claim 1 wherein the plant is a monocotyledonous or dicotyledonous plant.

16. The method according to claim 1 wherein the plant is an agricultural plant selected from the group consisting of Lithospermum erythrorhizon, Taxus spp, tobacco, cucurbits, carrot, vegetable brassica , melons, capsicums, grape vines, lettuce, strawberry, oilseed brassica , sugar beet, wheat, barley, maize, rice, soybeans, peas, sorghum, sunflower, tomato, potato, pepper, chrysanthemum , carnation, linseed, hemp and rye.

17. A plant cell comprising a heterologous nucleic acid encoding a DA1 protein having a disrupted or inactivated LIM-like domain, wherein the DA1 protein comprises an amino acid sequence having at least 90% sequence identity to one or more of SEQ ID NOs: 4 to 27, wherein the LIM-like domain of the DA1 protein comprises one or more sequence alterations relative to the wild-type LIM-like domain of SEQ ID NO: 28 which disrupt or inactivate the LIM-like domain, and wherein the wild-type LIM-like domain comprises two Zn finger motifs and the one or more sequence alterations abolish one or both Zn finger motifs.

18. A plant comprising the plant cell according to claim 17 .

19. A plant produced by the method according to claim 1 .