Methods and compositions for modifying levels of secondary metabolic compounds in plants

Abstract

The present invention provides a method of making a genetically transformed plant which has an altered content of at least one product of a secondary metabolic pathway. The method consists of introducing into a plant cell capable of being transformed and regenerated to a whole plant a DNA expression cassette. The expression cassette includes DNA sequences required for transformation and selection in plant cells. It also includes a DNA sequence that, under the control of a promoter active in plant cells, encodes a protein capable of modifying the utilization of a substrate in the secondary metabolic pathway. The substrate is not a primary metabolite of the group selected from glucose, amino acids, common fatty acids and nucleotides. A plant or plant tissues including seeds can then be recovered having an altered content of at least one product of the secondary metabolic pathway. The invention also provides for feed products derived from the plants and seeds obtained according to the method.

1 - 32 . (canceled)  
     
     
         33 . A genetically altered plant or a descendant thereof, comprising a recombinant nucleic acid molecule stably incorporated into the genome of said plant, said recombinant nucleic acid molecule comprising: 
 (a) a seed-specific promoter; and    (b) a nucleic acid sequence operably linked to said seed-specific promoter, said nucleic acid sequence encoding an enzyme capable of modifying the utilization of an intermediate substrate in a secondary metabolic pathway associated with a nutritional profile of a plant, said enzyme not naturally occurring in said secondary metabolic pathway;    said genetically altered plant being characterized by an improved nutritional profile relative to a wild-type of said plant;    or a cell, seed or component of said genetically altered plant or descendant thereof.    
     
     
         34 . The genetically altered plant or descendant thereof according to  claim 33 , wherein said secondary metabolic pathway is the phenylpropanoid pathway.  
     
     
         35 . The genetically altered plant or descendant thereof according to  claim 34 , wherein said enzyme acts on ferulic acid.  
     
     
         36 . The genetically altered plant or descendant thereof according to  claim 35 , wherein said enzyme is ferulic acid decarboxylase.  
     
     
         37 . The genetically altered plant or descendant thereof according to  claim 34 , wherein said improved nutritional profile comprises a reduced sinapine or lignin content relative to a wild-type of said plant.  
     
     
         38 . The genetically altered plant or descendant thereof according to  claim 33 , wherein said secondary metabolic pathway is the sugar alcohol secondary metabolic pathway.  
     
     
         39 . The genetically altered plant or descendant thereof according to  claim 38 , wherein said substrate is myo-inositol, galactinol, or a UDP-derivative of sugars.  
     
     
         40 . The genetically altered plant or descendant thereof according to  claim 38 , wherein said substrate is myo-inositol, and wherein said enzyme is an enzyme that acts upon myo-inositol.  
     
     
         41 . The genetically altered plant or descendant thereof according to  claim 38 , wherein said improved nutritional profile comprises a reduced phytic acid content relative to a wild-type of said plant.  
     
     
         42 . The genetically altered plant according to  claim 33 , wherein said plant is a member of a family of plants selected from Brassicaceae, Malvaceae, Linaceae, Compositae, Fabaceae, Euphorbicaceae, Gramineae and Oleaceae.  
     
     
         43 . The genetically altered plant according  claim 33 , wherein said plant is a member of a genus selected from  Brassica, Linum, Gossypium, Glycine, Arachis, Carthamus, Helianthus, Medicago, Sinapis, Raphanus, Ricinus, Olea, Zea, Hordium, Triticale  and  Oryza.    
     
     
         44 . The genetically altered plant or descendant thereof according to  claim 33 , wherein said plant is selected from corn, canola, wheat, barley, alfalfa, soybeans and sorghum.  
     
     
         45 . The genetically altered plant or descendant thereof according to  claim 33 , wherein said seed-specific promoter is a phaseolin promoter or a napin promoter.  
     
     
         46 . An animal feed derived at least in part from a genetically altered plant or descendant thereof according to  claim 33 , or from a cell, seed or component thereof.  
     
     
         47 . A method for making a genetically altered plant according to  claim 33 , comprising the steps of: 
 providing a nucleic acid sequence encoding an enzyme capable of modifying the utilization of an intermediate substrate in a secondary metabolic pathway associated with a nutritional profile of a plant, said enzyme not naturally occurring in said secondary metabolic pathway;    transforming a plant cell of said plant with an expression cassette comprising said nucleic acid sequence operably linked to a seed-specific promoter; and    recovering a genetically altered plant from said plant cell, said genetically altered plant characterized by an improved nutritional profile relative to a wild-type of said plant.    
     
     
         48 . The method according to  claim 47 , wherein said secondary metabolic pathway is the phenylpropanoid pathway.  
     
     
         49 . The method according to  claim 47 , wherein said secondary metabolic pathway is the sugar alcohol secondary metabolic pathway.  
     
     
         50 . The method according to  claim 47 , comprising the further step of growing said genetically altered plant under conditions that permit the formation of seed, and recovering said seed.