Methods for increasing stearate content in soybean oil

Abstract

This invention relates to a method for increasing stearate as a component of total triglycerides found in soybean seed. The method generally comprises growing a soybean plant having integrated into its genome a DNA construct comprising, in the 5′ to 3′ direction of transcription, a promoter functional in a soybean plant seed cell, a DNA sequence encoding an acyl-ACP thioesterase protein having substantial activity on C18:0 acyl-ACP substrates, and a transcription termination region functional in a plant cell. The present invention also provides a soybean seed with about 33 weight percent or greater stearate as a component of total fatty acids found in seed triglycerides.

What is claimed is:  
     
         1 . A method for increasing stearate as a component of total triglycerides found in soybean seed, wherein said method comprises: 
 growing a soybean plant having integrated into its genome a DNA construct, said construct comprising in the 5′ to 3′ direction of transcription, a promoter functional in a soybean plant seed cell, a DNA sequence encoding an acyl-ACP thioesterase protein having substantial activity on C18:0 acyl-ACP substrates, and a transcription termination region functional in a plant cell.    
     
     
         2 . The method of  claim 1 , wherein said encoding sequence has little or no activity on C16:0 substrates.  
     
     
         3 . The method of  claim 1  wherein said thioesterase encoding sequence is from the genus Garcinia.  
     
     
         4 . The method of  claim 1 , wherein said DNA sequence encodes the Garm FatA1 thioesterase presented in FIG. 1.  
     
     
         5 . The method of  claim 1 , wherein said promoter is from a gene preferentially expressed in plant seed tissue.  
     
     
         6 . The method according to  claim 1 , wherein said promoter is the napin promoter.  
     
     
         7 . The method according to  claim 1 , wherein said promoter is from the soybean β-conglycinin 7S subunit transcription initiation region.  
     
     
         8 . The method of  claim 1 , wherein said plant seed triglycerides comprise about 20 weight percent or greater stearate.  
     
     
         9 . The method of  claim 1 , wherein said plant seed triglycerides comprise about 33 weight percent or greater stearate.  
     
     
         10 . The method of  claim 1 , wherein said plant seed triglycerides comprise about 40 weight percent or greater stearate.  
     
     
         11 . The method of  claim 1 , wherein said plant seed triglycerides comprise about 50 weight percent or greater stearate.  
     
     
         12 . A soybean seed comprising about 33 weight percent or greater stearate as a component of total fatty acids found in seed triglycerides.  
     
     
         13 . The soybean seed according to  claim 12  comprising about 40 weight percent or greater stearate as a component of said seed triglycerides.  
     
     
         14 . The soybean seed according to  claim 13  comprising about 50 weight percent or greater stearate as a component of said seed triglycerides.  
     
     
         15 . The soybean seed according to  claim 12  comprising about 50 percent or greater stearate as the fatty acid found at the sn-1 and sn-3 positions of seed triglycerides.  
     
     
         16 . The soybean seed according to  claim 13  comprising about 60 percent or greater stearate as the fatty acid found in said sn-1 and sn-3 positions of seed triglycerides.  
     
     
         17 . The soybean seed according to  claim 14  comprising about 75 percent or greater stearate as the fatty acid found in said sn-1 and sn-3 positions of seed triglycerides.  
     
     
         18 . Soybean seed according to  claim 15 , and comprising oleic acid as the predominant fatty acid at the sn-2 position of seed triglycerides.  
     
     
         19 . Seed oil obtained from seed of  claim 12 .  
     
     
         20 . A shortening comprising the seed oil of  claim 19 .  
     
     
         21 . A soybean plant having seed comprising about 50 weight percent or greater saturated fatty as a component total fatty acids found in seed triglycerides.  
     
     
         22 . The soybean plant according to  claim 21  wherein said saturated fatty acid component is about 60 weight percent or greater.  
     
     
         23 . The soybean plant according to  claim 22  wherein said saturated fatty acid component is about 65 weight percent or greater.  
     
     
         24 . A soybean plant having seed comprising about 20 weight percent or greater stearate and about 15 weight percent or less oleate as components of total fatty acids found in seed triglycerides.  
     
     
         25 . The soybean plant according to  claim 24  wherein said stearate content is greater than about 33% of the total fatty acid composition.  
     
     
         26 . A vegetable oil-based edible spread comprising a high stearate soybean oil.  
     
     
         27 . The vegetable oil-based edible spread of  claim 26 , wherein said soybean oil comprises a stearate level of about 20 weight percent or greater.  
     
     
         28 . The vegetable oil-based edible spread of  claim 26 , wherein said soybean oil is the seed oil of the mutant soybean variety HS2.  
     
     
         29 . The vegetable oil-based edible spread of  claim 26 , wherein said soybean oil is the seed oil of  claim 19 .  
     
     
         30 . A frying oil comprising a high stearate soybean oil.  
     
     
         31 . The frying oil of  claim 30 , wherein said soybean oil comprises a stearate level of about 20 weight percent or greater.  
     
     
         32 . The frying oil of  claim 30 , wherein said soybean oil is the seed oil of the mutant soybean variety HS2.  
     
     
         33 . The frying oil of  claim 30 , wherein said soybean oil is the seed oil of  claim 19 .  
     
     
         34 . A cocoa butter substitute comprising a high stearate soybean oil.  
     
     
         35 . The cocoa butter substitute of  claim 34 , wherein said soybean oil comprises a stearate level of about 20 weight percent or greater.  
     
     
         36 . The cocoa butter substitute of  claim 34 , wherein said soybean oil is the seed oil of the mutant soybean variety HS2.  
     
     
         37 . The cocoa butter substitute of  claim 34 , wherein said soybean oil is the seed oil of  claim 19 .  
     
     
         38 . A cocoa butter equivalent comprising a high stearate soybean oil.  
     
     
         39 . The cocoa butter equivalent of  claim 38 , wherein said soybean oil comprises a stearate level of about 20 weight percent or greater.  
     
     
         40 . The cocoa butter equivalent of  claim 38 , wherein said soybean oil is the seed oil of the mutant soybean variety HS2.  
     
     
         41 . The cocoa butter equivalent of  claim 38 , wherein said soybean oil is the seed oil of  claim 19 .  
     
     
         42 . A soymilk produced from soybean seed having a high stearate oil.  
     
     
         43 . The soymilk of  claim 42 , wherein said oil comprises a stearate level of about 20 weight percent or greater.  
     
     
         44 . The soymilk of  claim 42 , wherein said oil is the seed oil of the mutant soybean variety HS2.  
     
     
         45 . The soymilk of  claim 42 , wherein said oil is the seed oil of  claim 19 .  
     
     
         46 . A tofu product produced from soybean seed having a high stearate oil.  
     
     
         47 . The tofu product of  claim 46 , wherein said oil comprises a stearate level of about 20 weight percent or greater.  
     
     
         48 . The tofu product of  claim 46 , wherein said oil is the seed oil of the mutant soybean variety HS2.  
     
     
         49 . The tofu product of  claim 46 , wherein said oil is the seed oil of  claim 19 .  
     
     
         50 . A flour produced from soybean seed having a high stearate oil.  
     
     
         51 . The flour of  claim 50 , wherein said oil comprises a stearate level of about 20 weight percent or greater.  
     
     
         52 . The flour of  claim 50 , wherein said oil is the seed oil of the mutant soybean variety HS2.  
     
     
         53 . The flour of  claim 50 , wherein said oil is the seed oil of  claim 19.