Materials and methods for increasing the tocopherol content in seed oil
The present invention relates generally to the field of molecular biology and concerns increasing the tocopherol content of a plant relative to a control plant, comprising expressing in a plant at least one polynucleotide encoding a delta-12-desaturase, at least one polynucleotide encoding a delta-6-desaturase, at least one polynucleotide encoding a delta-6-elongase, and at least one polynucleotide encoding a delta-5-desaturase. The present invention also relates to methods for the manufacture of oil, fatty acid- or lipids-containing compositions, and to such oils and lipids as such.
1. A method for increasing total tocopherol content of a plant relative to a control plant, comprising:
(a) providing a transgenic plant transformed with multiple expression cassettes comprising transgenes which comprise at least one polynucleotide encoding a delta-12-desaturase from Phythophthora species, at least one polynucleotide encoding a delta-6-desaturase from Ostreococcus species, at least one polynucleotide encoding a delta-6-elongase from Physcomitrella species or Thalassiosira species, and at least one polynucleotide encoding a delta-5-desaturase from Thraustochytrium species;
(b) obtaining transgenic seed oil from the transgenic plant; and
(c) measuring total tocopherol content in said transgenic seed oil,
wherein said transgenic seed oil has increased total tocopherol content as compared to a control plant of the same species, wherein the transgenic plant is an oilseed plant of the genus Brassica , and wherein expression of said transgenes in said transgenic plant results in said increase in total tocopherol content in said transgenic seed oil.
2. The method according to claim 1 , wherein said multiple expression cassettes further comprise a transgene which comprises at least one polynucleotide encoding an omega-3-desaturase from Phythophthora species or Pythium species, and wherein said omega-3-desaturase is expressed in said transgenic plant.
3. The method according to claim 1 , wherein said multiple expression cassettes further comprise a transgene which comprises at least one polynucleotide encoding a delta-5-elongase from Ostreococcus species, and wherein said delta-5-elongase is expressed in said transgenic plant.
4. The method according to claim 1 , wherein said multiple expression cassettes further comprises a transgene which comprises at least one polynucleotide encoding a delta-4-desaturase from Thraustochytrium species or Pavlova species, and wherein said delta-4-desaturase is expressed in said transgenic plant.
5. The method of claim 1 , wherein said delta-6 elongase is from Physcomitrella patens or Thalassiosira pseudonana ; said delta-12 desaturase is from Phythophthora sojae ; and said delta-6 desaturase is from Ostreococcus tauri.
6. The method of claim 1 , wherein said polynucleotides are present on one T-DNA or recombinant DNA construct having said multiple expression cassettes which are stably integrated in the genome of the transgenic plant.
7. The method of claim 2 , wherein said omega-3-desaturase is from Phythophthora infestans or Pythium irregular.
8. The method of claim 3 , wherein said delta-5 elongase is from Ostreococcus tauri.
9. The method of claim 4 , wherein said delta-4 desaturase is from Thraustochytrium species or Pavlova lutheri.
10. The method according to claim 1 , wherein said multiple expression cassettes further comprise a transgene which comprises at least one polynucleotide encoding an omega-3-desaturase from Phythophthora species or Pythium species, a transgene which comprises at least one polynucleotide encoding a delta-5-elongase from Ostreococcus species, and a transgene which comprises at least one polynucleotide encoding a delta-4-desaturase from Thraustochytrium species or Pavlova species.
11. The method of claim 10 , wherein said delta-6 elongase is from Physcomitrella patens or Thalassiosira pseudonana ; said delta-12 desaturase is from Phythophthora sojae ; said delta-6 desaturase is from Ostreococcus tauri ; said omega-3 desaturase is from Pythium irregular or Phythophthora infestans ; said delta-5 elongase is from Ostreococcus tauri ; and said delta-4 desaturase is from Thraustochytrium species or Pavlova lutheri.