Modified plants

Abstract

A method for controlling endosperm size and development in plants. The method employs nucleic acid constructs encoding proteins involved in genomic imprinting, in the production of transgenic plants. The nucleic acid constructs can be used in the production of transgenic plants to affect interspecific hybridisation.

1 . A transgenic plant containing a transgene comprising a nucleic acid sequence having at least 85% identity to a full  Arabidopsis  DNA methyltransferase 1 nucleic acid sequence that is effective for reducing levels of general DNA methylation, said nucleic acid sequence operably linked to a gynoecium-specific promoter.  
     
     
         2 . The plant of  claim 1 , wherein said plant is a dicotyledonous plant.  
     
     
         3 . The plant of  claim 1 , wherein said nucleic acid sequence comprises an antisense sequence to DNA that encodes the  Arabidopsis  DNA methyltransferase 1 sequence.  
     
     
         4 . The plant of  claim 1 , wherein said nucleic acid sequence is transcribed into a double strand RNA.  
     
     
         5 . The plant of  claim 1 , wherein said nucleic acid sequence comprises a sense sequence to the  Arabidopsis  DNA methyltransferase 1 sequence.  
     
     
         6 . The plant of  claim 1 , wherein said gynoecium-specific promoter is a female germ line promoter.  
     
     
         7 . The plant of  claim 1 , wherein seeds that develop on said plant, after pollination by pollen that lacks said transgene, have a mean seed weight that is at least 33% greater than the mean seed weight of seeds that develop on a corresponding plant that lacks said nucleic acid sequence.  
     
     
         8 . The plant of  claim 7 , wherein said seeds are viable.  
     
     
         9 . A method for the production of seeds, comprising the step of permitting self-pollination of a plant comprising a transgene comprising a nucleic acid sequence having at least 85% identity to a full  Arabidopsis  DNA methyltransferase 1 nucleic acid sequence that is effective for reducing levels of general DNA methylation, said nucleic acid sequence operably linked to a gynoecium-specific promoter, wherein seeds that develop on said plant have increased mean seed weight compared to the mean seed weight of seeds that develop on a corresponding self-pollinated plant that lacks said nucleic acid sequence.  
     
     
         10 . The method of  claim 9 , wherein said plant is a dicotyledonous plant.  
     
     
         11 . The method of  claim 9 , wherein said nucleic acid sequence comprises an antisense sequence to the  Arabidopsis  DNA methyltransferase 1 sequence.  
     
     
         12 . The method of  claim 9 , wherein said nucleic acid sequence is transcribed into a double strand RNA.  
     
     
         13 . The method of  claim 9 , wherein said nucleic acid sequence comprises a sense sequence to the  Arabidopsis  DNA methyltransferase 1 sequence.  
     
     
         14 . The method of  claim 9 , wherein said seeds are viable.  
     
     
         15 . The method of  claim 9 , wherein said gynoecium-specific promoter is a female germ line promoter.  
     
     
         16 . The method of  claim 9 , wherein seeds that develop on said plant have a mean seed weight that is at least 33% greater than the mean seed weight of seeds that develop on a corresponding plant that lacks said nucleic acid sequence.  
     
     
         17 . A method for the production of seeds, comprising the step of permitting cross-pollination of a plant comprising a transgene comprising a nucleic acid sequence having at least 85% identity to a full  Arabidopsis  DNA methyltransferase 1 nucleic acid sequence that is effective for reducing levels of general DNA methylation, said nucleic acid sequence operably linked to a gynoecium-specific promoter, wherein seeds that develop on said plant have increased mean seed weight compared to the mean seed weight of seeds that develop on a corresponding self-pollinated plant that lacks said nucleic acid sequence.  
     
     
         18 . The method of  claim 17 , wherein said plant is a dicotyledonous plant.  
     
     
         19 . The method of  claim 17 , wherein said nucleic acid sequence comprises an antisense sequence to the  Arabidopsis  DNA methyltransferase 1 sequence.  
     
     
         20 . The method of  claim 17 , wherein said nucleic acid sequence is transcribed into a double strand RNA.  
     
     
         21 . The method of  claim 17 , wherein said nucleic acid sequence comprises a sense sequence to the  Arabidopsis  DNA methyltransferase 1 sequence.  
     
     
         22 . The method of  claim 17 , wherein said gynoecium-specific promoter is a female germ line promoter.  
     
     
         23 . The method of  claim 17 , wherein seeds that develop on said plant have a mean seed weight that is at least 33% greater than the mean seed weight of seeds that develop on a corresponding plant that lacks said nucleic acid sequence.