Patent
This disclosure provides Chlamydomonas violaxanthin de-epoxidase (CVDE) gene, polypeptides, and variants thereof as well as host cells that are genetically modified to express a CVDE polypeptide or variant. The disclosure additionally provides methods of producing such a genetically modified host cell and methods of using the cells , e.g., to increase zeaxanthin production.
1. An expression vector comprising a polynucleotide that comprises a nucleic acid sequence encoding a polypeptide having at least 95% identity to amino acids 57-876 of SEQ ID NO:1.
2. The expression vector of claim 1 , wherein the polynucleotide comprises a nucleic acid sequence encoding a heterologous chloroplast transit peptide joined to the polypeptide.
3. The expression vector of claim 1 , wherein the nucleic acid sequence encoding the polypeptide is operably linked to a heterologous promoter.
4. The expression vector of claim 1 , wherein the polypeptide comprises the amino acids 57-876 of SEQ ID NO:1.
5. A host cell comprising the expression vector of claim 1 .
6. The host cell of claim 5 , wherein the host cell is a plant.
7. The host cell of claim 5 , wherein the host cell is a eukaryotic alga.
8. A host cell comprising a polynucleotide comprising a nucleic acid sequence encoding a polypeptide having at least 95% identity to amino acids 57-876 of SEQ ID NO:1, wherein the host cell is from a photosynthetic organism and the nucleic acid sequence encoding the polypeptide is operably linked to a heterologous promoter.
9. The host cell of claim 8 , wherein the nucleic acid sequence encoding the polypeptide is codon optimized for expression in the host cell.
10. The host cell of claim 8 , wherein the polynucleotide comprises a nucleic acid sequence encoding a heterologous chloroplast transit peptide joined to the polypeptide.
11. The host cell of claim 8 , wherein the polypeptide comprises amino acids 57-876 of SEQ ID NO:1.
12. The host cell of claim 8 , wherein the photosynthetic organism is a plant.
13. The host cell of claim 8 , wherein the photosynthetic organism is a eukaryotic alga.
14. A method of increasing the kinetics of non-photochemical quenching or increasing zeaxanthin production in a photosynthetic organism, the method comprising genetically modifying the photosynthetic organism to overexpress a polypeptide having at least 95% identity to amino acids 57-876 of SEQ ID NO:1 in the plant; thereby increasing the kinetics of non-photochemical quenching or increasing zeaxanthin production relative to a counterpart plant of the same strain that is not genetically modified to overexpress the polypeptide.
15. The method of claim 14 , wherein the photosynthetic organism is a plant.
16. The method of claim 14 , wherein the photosynthetic organism is a eukaryotic alga.
17. A photosynthetic organism obtained by the method of claim 14 .
18. The photosynthetic organism of claim 17 , wherein the photosynthetic organism is a plant.
19. The photosynthetic organism of claim 17 , wherein the photosynthetic organism is a eukaryotic alga.
20. The host cell of claim 8 , wherein the polypeptide has at least 99% identity to amino acids 57-876 of SEQ ID NO:1.