Dgat genes for increased seed storage lipid production and altered fatty acid profiles in oilseed plants

Abstract

Polynucleotide sequences encoding diacylglycerol acyltransferase genes and the use of these acyltransferases for increased seed storage lipid production and altered fatty acid profiles in oilseed plants are disclosed. Transgenic soybean seed having increased total fatty acid content of at least 20% and altered fatty acids when compared to the total fatty acid content of non-transgenic, null segregant soybean seed are described. Methods for increasing the total fatty acid content of a soybean seed by at least 20% include steps of transformation and selection.

What is claimed is: 
     
         1 . A transgenic soybean seed having an increased total fatty acid content of at least 20% and a decreased stachyose content when compared to the total fatty acid content and stachyose content of a non-transgenic, null segregant soybean seed, wherein the seed comprises at least one recombinant construct having at least one diacylglycerol acyltransferase (DGAT) sequence and a construct downregulating galactinol synthase (GAS) activity wherein the DGAT sequence and the GAS construct can be in the same recombinant construct or in separate recombinant constructs. 
     
     
         2 . The transgenic soybean seed of  claim 1  further wherein the DGAT sequence is a  Yarrowia  DGAT sequence. 
     
     
         3 . The transgenic soybean seed of  claim 1 , wherein the DGAT sequence is a DGAT1. 
     
     
         4 . The transgenic soybean seed of  claim 1 , wherein the DGAT sequence is a DGAT2. 
     
     
         5 . The transgenic soybean seed of  claim 1 , wherein the transgenic soybean seed has an increased protein content and decreased raffinose content when compared to the protein content and raffinose content of the non-transgenic, null segregant soybean seed. 
     
     
         6 . The transgenic soybean seed of  claim 1 , wherein the transgenic soybean seed has a decreased raffinose content when compared to the raffinose content of the non-transgenic, null segregant soybean seed. 
     
     
         7 . The transgenic soybean seed of  claim 1 , wherein the transgenic soybean seed has an increased total fatty acid content of at least 25% when compared to the total fatty acid content of the non-transgenic, null segregant soybean seed. 
     
     
         8 . A method for increasing the total fatty acid content and decreasing the stachyose content of a soybean seed, the method comprising:
 (a) transforming at least one soybean cell with at least one recombinant construct having at least one diacylglycerol acyltransferase (DGAT) sequence and a construct downregulating galactinol synthase (GAS) activity wherein the DGAT sequence and the GAS construct can be in the same recombinant construct or in separate recombinant constructs;   (b) selecting the transformed soybean cell(s) of step (a) such that plants grown from the transformed cells produce transgenic seed having an increased total fatty acid content of at least 20% and a decreased stachyose content when compared to the total fatty acid content and stachyose content of a non-transgenic, null segregant soybean seed.   
     
     
         9 . The method of  claim 8 , wherein the DGAT sequence is a DGAT1. 
     
     
         10 . The method of  claim 8 , wherein the DGAT sequence is a DGAT2. 
     
     
         11 . The method of  claim 8 , wherein the DGAT sequence is a  Yarrowia  sequence. 
     
     
         12 . The method of  claim 8 , wherein the transgenic seed has an increased total fatty acid content of at least 25%. 
     
     
         13 . The method of  claim 8 , wherein the transgenic soybean seed has increased protein content and decreased raffinose content when compared to the protein content and raffinose content of the non-transgenic, null segregant soybean seed. 
     
     
         14 . The method of  claim 8 , wherein the the transgenic soybean seed has a decreased raffinose content when compared to the raffinose content of the non-transgenic, null segregant soybean seed. 
     
     
         15 . A meal obtained from a transgenic soybean seed having increased total fatty acid content of at least 20% when compared to the total fatty acid content of a non-transgenic, null segregant soybean seed, wherein the transgenic soybean seed comprises at least one recombinant construct having at least one diacylglycerol acyltransferase (DGAT) sequence and a construct downregulating galactinol synthase (GAS) activity wherein the DGAT sequence and the GAS construct can be in the same recombinant construct or in separate recombinant constructs, further wherein the soluble carbohydrate content of the meal is reduced by at least 17% when compared to the soluble carbohydrate content of a meal obtained from a non-transgenic, null segregant soybean seed. 
     
     
         16 . The meal of  claim 15 , wherein the DGAT sequence is a  Yarrowia  DGAT sequence. 
     
     
         17 . The meal of  claim 15 , wherein the soluble carbohydrate is stachyose. 
     
     
         18 . The meal of  claim 15 , wherein the soluble carbohydrate is raffinose. 
     
     
         19 . The meal of  claim 15 , wherein the transgenic soybean seed has an increased total fatty acid content of at least 25%. 
     
     
         20 . The meal of  claim 19 , wherein the protein content is increased by at least 1.5% points in the meal obtained from the transgenic soybean seed compared to the protein content of a meal obtained from the non-transgenic null segregant soybean seed.