Proceedings of the National Academy of Sciences - PNAS, 2006-06, Vol.103 (25), p.9446-9451
2006
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- Autor(en) / Beteiligte
- Titel
- Identification of bifunctional delta12/omega3 fatty acid desaturases for improving the ratio of omega3 to omega6 fatty acids in microbes and plants
- Ist Teil von
- Proceedings of the National Academy of Sciences - PNAS, 2006-06, Vol.103 (25), p.9446-9451
- Ort / Verlag
- United States
- Erscheinungsjahr
- 2006
- Quelle
- Free E-Journal (出版社公開部分のみ）
- Beschreibungen/Notizen
- We report the identification of bifunctional delta12/omega3 desaturases from Fusarium moniliforme, Fusarium graminearum, and Magnaporthe grisea. The bifunctional activity of these desaturases distinguishes them from all known delta12 or omega3 fatty acid desaturases. The omega3 desaturase activity of these enzymes also shows a broad omega6 fatty acid substrate specificity by their ability to convert linoleic acid (LA), γ-linolenic acid, di-homo-γ-linolenic acid, and arachidonic acid to the omega3 fatty acids, α-linolenic acid (ALA), stearidonic acid, eicosatetraenoic acid, and eicosapentaenoic acid (EPA), respectively. Phylogenetic analysis suggests that omega3 desaturases arose by independent gene duplication events from a delta12 desaturase ancestor. Expression of F. moniliforme delta12/omega3 desaturase resulted in high ALA content in both Yarrowia lipolytica, an oleaginous yeast naturally deficient in omega3 desaturation, and soybean. In soybean, seed-specific expression resulted in 70.9 weight percent of total fatty acid (%TFA) ALA in a transformed seed compared with 10.9%TFA in a null segregant seed and 53.2%TFA in the current best source of ALA, linseed oil. The ALA/LA ratio in transformed seed was 22.3, a 110- and 7-fold improvement over the null segregant seed and linseed oil, respectively. Thus, these desaturases have potential for producing nutritionally desirable omega3 long-chain polyunsaturated fatty acids, such as EPA, with a significantly improved ratio of omega3/omega6 long-chain polyunsaturated fatty acids in both oilseeds and oleaginous microbes.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 0027-8424eISSN: 1091-6490Titel-ID: cdi_proquest_miscellaneous_68103904
- Format
- –
- Schlagworte
- arachidonic acid, Bacteria - chemistry, Bacteria - classification, Bacteria - enzymology, Bacteria - genetics, bifunctional enzymes, chloroplast DNA, domestication, enzyme activity, enzymology, fatty acid composition, Fatty Acid Desaturases - classification, Fatty Acid Desaturases - genetics, Fatty Acid Desaturases - metabolism, Fatty Acids, Omega-3 - metabolism, Fatty Acids, Omega-6 - metabolism, fatty-acid synthase, Fungi - chemistry, Fungi - classification, Fungi - enzymology, Fungi - genetics, gene expression, gene transfer, genes, genetic variation, genetically engineered microorganisms, Gibberella fujikuroi, Gibberella zeae, Glycine max, Glycine max - enzymology, Glycine max - genetics, haplotypes, linoleic acid, linolenic acid, Magnaporthe grisea, Molecular Sequence Data, nuclear genes, nuclear genome, nucleotide sequences, Oryza rufipogon, Oryza sativa, Phylogeny, phylogeography, Plants - chemistry, Plants - classification, Plants - enzymology, Plants - genetics, rice, Saccharomycetales, seeds, soybeans, Substrate Specificity, transgenic plants, wild relatives, Yarrowia - enzymology, Yarrowia - genetics, Yarrowia lipolytica