Production of omega 3 long chain polyunsaturated fatty acids in oilseed crops by a thraustochytrid PUFA synthase
This disclosure concerns recombinant host organisms genetically modified with a polyunsaturated fatty acid (PUFA) synthase system and one or more accessory proteins that allow for and/or improve the production of PUFAs in the host organism. The disclosure also concerns methods of making and using such organisms as well as products obtained from such organisms.
1. A plant expression construct comprising:
(A) a first expression cassette comprising
a first promoter that is functional in a plant cell, and
a first polynucleotide encoding a first polyunsaturated fatty acid (PUFA) synthase system polypeptide comprising an amino acid sequence that is at least 95% identical to SEQ ID NO:1,
wherein the first polynucleotide is operably linked to the first promoter;
(B) a second expression cassette comprising
a second promoter that is functional in a plant cell, and
a second polynucleotide encoding a second PUFA synthase system polypeptide comprising an amino acid sequence that is at least 95% identical to SEQ ID NO:4,
wherein the second polynucleotide is operably linked to the second promoter;
(C) a third expression cassette comprising
a third promoter that is functional in a plant cell, and
a third polynucleotide encoding a third PUFA synthase system polypeptide comprising an amino acid sequence that is at least 95% identical to SEQ ID NO:14,
wherein the third polynucleotide is operably linked to the third promoter; and
(D) a fourth expression cassette comprising
a fourth promoter that is functional in a plant cell, and
a fourth polynucleotide encoding a phosphopantetheinyl transferase (PPTase) polypeptide comprising an amino acid sequence that is at least 95% identical to SEQ ID NO:39,
wherein the fourth polynucleotide is operably linked to the fourth promoter,
wherein the expression cassettes are arranged in a tail-to-tail or head-to-head orientation in the construct.
2. The plant expression construct of claim 1 ,
wherein the construct further comprises
(E) a fifth expression cassette comprising
a fifth promoter that is functional in a plant cell, and
a fifth polynucleotide encoding an acyl-CoA synthetase polypeptide comprising an amino acid sequence that is at least 95% identical to SEQ ID NO:40,
wherein the fifth polynucleotide is operably linked to the fifth promoter.
3. The plant expression construct of claim 1 , wherein the expression cassettes are arranged in a tail to tail orientation in the construct.
4. The plant expression construct of claim 1 , wherein the expression cassettes each further comprise a 5′ UTR, a 3′ UTR, and a termination sequence.
5. The plant expression construct of claim 1 , wherein each of the promoters is a seed-specific promoter.
6. The plant expression construct of claim 5 , wherein the promoters are not the same.
7. The plant expression construct of claim 1 , wherein the expression cassettes are arranged in the 5′ to 3′ order A-D-C-B.
8. A seed comprising the plant expression construct of claim 1 , the seed comprising at least one polyunsaturated fatty acid (PUFA) selected from the group consisting of eicosapentaenoic acid (C20:5) (EPA), gamma-linolenic acid (C18:3) (GLA), and arachidonic acid (20:4) (ARA).
9. The seed of claim 8 , wherein the seed is a soybean seed or a canola seed.
10. A plant producing the seed of claim 8 , the plant comprising the plant expression construct.
11. A cell, tissue, or part of the plant of claim 10 , the cell, tissue, or part comprising the plant expression construct.
12. A genetically-modified plant commodity product comprising the plant expression construct of claim 1 .
13. The genetically-modified plant commodity product of claim 12 , wherein the product is a feed or meal composition or a functional food product.
14. The genetically-modified plant commodity product of claim 12 , wherein the product is an oil.
15. The oil of claim 14 , wherein the oil comprises at least one polyunsaturated fatty acid (PUFA) selected from the group consisting of eicosapentaenoic acid (C20:5) (EPA), gamma-linolenic acid (C18:3) (GLA), and arachidonic acid (20:4) (ARA).
16. The oil of claim 15 , wherein the oil is a raw or unmodified oil.
17. The oil of claim 15 , wherein the oil is a soybean oil or a canola oil.
18. A method for obtaining an oil comprising at least one PUFA, the method comprising recovering an oil from the seed of claim 8 .
19. A method for producing an oil comprising at least one PUFA, the method comprising cultivating the plant of claim 10 to produce a seed comprising the oil.