Raffinose synthase gene, method for producing raffinose, and transgenic plant

Abstract

Raffinose synthase purified from cucumber is allowed to act on sucrose and galactinol. Thus raffinose is efficiently produced. The function of endogenous raffinose synthase is regulated by transforming a plant with a chimeric gene comprising a raffinose synthase gene and a regulatory region expressible in the plant. Thus a plant, in which raffinose family oligosaccharides are decreased, is created.

1 - 12 . Canceled.  
     
     
         13 . A method of producing a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol, comprising screening a cDNA library prepared from a plant by hybridization using a probe whose sequence is a portion of the nucleotide sequence of SEQ ID NO: 4, to select the DNA.  
     
     
         14 . A method of producing a vector comprising a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol, comprising producing the DNA by the method of  claim 13 , and inserting the DNA to a vector.  
     
     
         15 . A method of producing a transformed plant, comprising producing a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol by the method of  claim 13 , and transforming a plant with the DNA.  
     
     
         16 . A method according to  claim 15 , wherein the plant is soybean, rapeseed, cotton, sugar beet, or sugar cane.  
     
     
         17 . A method of producing a chimeric gene comprising a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol, operably linked to a transcription regulatory region expressible in plant cells, comprising producing the DNA by the method of  claim 13 , and operably linking the DNA to the transcription regulatory region expressible in plant cells.  
     
     
         18 . A method of producing a transformed plant, comprising producing a chimeric gene comprising a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol, operably linked to a transcription regulatory region expressible in plant cells, by the method of  claim 17 , and transforming a plant with the chimeric gene.  
     
     
         19 . The method according to  claim 18 , wherein the plant is soybean, rapeseed, cotton, sugar beet, or sugar cane.  
     
     
         20 . A method of modifying the content of raffinose family oligosaccharides in a plant, comprising producing a chimeric gene comprising a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol, operably linked to a transcription regulatory region expressible in plant cells, by the method of  claim 17 , and transforming the plant with the chimeric gene, thereby changing the content of raffinose family oligosaccharides in the plant.  
     
     
         21 . A method of producing a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol, comprising subjecting a DNA coding for a protein comprising SEQ ID NO: 5 to a mutagenesis and screening for a mutant DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol.  
     
     
         22 . A method of producing a vector comprising a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol, comprising producing the DNA by the method of  claim 21 , and inserting the DNA to a vector.  
     
     
         23 . A method of producing a transformed plant, comprising producing a DNA which odes for a protein having an activity to produce raffinose from sucrose and galactinol by the method of  claim 21 , and transforming a plant with the DNA.  
     
     
         24 . The method according to  claim 23 , wherein the plant is soybean, rapeseed, cotton, sugar beet, or sugar cane.  
     
     
         25 . A method of producing a chimeric gene comprising a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol, operably linked to a transcription regulatory region expressible in plant cells, comprising producing the DNA by the method of  claim 21 , and operably linking the DNA to the transcription regulatory region expressible in the plant cells.  
     
     
         26 . A method of producing a transformed plant, comprising producing a chimeric gene comprising a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol, operably linked to a transcription regulatory region expressible in plant cells, by the method of  claim 25 , and transforming a plant with the chimeric gene.  
     
     
         27 . The method according to  claim 26 , wherein the plant is soybean, rapeseed, cotton, sugar beet, or sugar cane.  
     
     
         28 . A method of modifying the content of raffinose family oligosaccharides in a plant, which method comprising producing a chimeric gene comprising a DNA which codes for a protein having an activity to produce raffinose from sucrose and galactinol, operably linked to a transcription regulatory region expressible in plant cells, by the method of  claim 25 , and transforming the plant with the chimeric gene, thereby changing the content of raffinose family oligosaccharides in the plant.