Co-expression of the borage Δ6 desaturase and the Arabidopsis Δ15 desaturase results in high accumulation of stearidonic acid in the seeds of transgenic soybean

Eckert, Hélène; LaVallee, Brad; Schweiger, Bruce; Kinney, Anthony J.; Cahoon, Edgar B.; Clemente, Tom

doi:10.1007/s00425-006-0291-3

Cited by 102 publications

(70 citation statements)

References 32 publications

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“…Even more dramatic was the increase in 3͞ 6 ratio in soybeans, which was as high as Ϸ22, a 6-fold increase over linseed oil. Seed-specific expression of Arabidopsis 3 desaturase (FAD3) in soybean resulted in 53.0%TFA ALA (34). Seed-specific expression of a flax 3 desaturase in a double mutant of flax lacking both FAD3 genes resulted in 41.0%TFA ALA in seeds (32).…”

Section: Discussionmentioning

confidence: 99%

Identification of bifunctional Δ12/ω3 fatty acid desaturases for improving the ratio of ω3 to ω6 fatty acids in microbes and plants

Damude

Zhang

Farrall

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

164

120

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We report the identification of bifunctional ⌬12͞ 3 desaturases from Fusarium moniliforme, Fusarium graminearum, and Magnaporthe grisea. The bifunctional activity of these desaturases distinguishes them from all known ⌬12 or 3 fatty acid desaturases. The 3 desaturase activity of these enzymes also shows a broad 6 fatty acid substrate specificity by their ability to convert linoleic acid (LA), ␥-linolenic acid, di-homo-␥-linolenic acid, and arachidonic acid to the 3 fatty acids, ␣-linolenic acid (ALA), stearidonic acid, eicosatetraenoic acid, and eicosapentaenoic acid (EPA), respectively. Phylogenetic analysis suggests that 3 desaturases arose by independent gene duplication events from a ⌬12 desaturase ancestor. Expression of F. moniliforme ⌬12͞ 3 desaturase resulted in high ALA content in both Yarrowia lipolytica, an oleaginous yeast naturally deficient in 3 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 ALA͞LA 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 3 longchain polyunsaturated fatty acids, such as EPA, with a significantly improved ratio of 3͞ 6 long-chain polyunsaturated fatty acids in both oilseeds and oleaginous microbes. polyunsaturated fatty acids ͉ Yarrowia ͉ soybean

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Section: Discussionmentioning

confidence: 99%

Identification of bifunctional Δ12/ω3 fatty acid desaturases for improving the ratio of ω3 to ω6 fatty acids in microbes and plants

Damude

Zhang

Farrall

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

164

120

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“…4A) is dominated by a mixture of 16:0, 16:4⌬ 4,7,10,13 , and 18:3⌬ 9,12,15 acyl chains. In the CC-620 background, the -3 polyunsaturated fatty acid (PUFA) species are quantitatively replaced with the presumed precursor species, 16:3⌬ 4,7,10 and 18:2⌬ 9,12 , demonstrating a loss of the -3 desaturase activity required for generation of the chloroplast-specific -3 FA 16:4⌬ 4,7,10,13 . Likewise for the cytoplasmic compartment (Fig.…”

Section: Fig 3 C Reinhardtii Strain Cc-620 Lacks -3 Fatty Acid Specimentioning

confidence: 99%

A High-Throughput Fatty Acid Profiling Screen Reveals Novel Variations in Fatty Acid Biosynthesis in Chlamydomonas reinhardtii and Related Algae

et al. 2014

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Analysis of fatty acid methyl esters (FAMEs) by gas chromatography (GC) is a common technique for the quantitative and qualitative analysis of acyl lipids. Methods for FAME preparation are typically time-consuming and labor-intensive and require multiple transfers of reagents and products between reaction tubes and autosampler vials. In order to increase throughput and lower the time and materials costs required for FAME preparation prior to GC analysis, we have developed a method in which 10-to-20-mg samples of microbial biomass are transferred to standard GC autosampler vials, transesterified using an emulsion of methanolic trimethylsulfonium hydroxide and hexane, and analyzed directly by GC without further sample handling. This method gives results that are essentially identical to those obtained by the more labor-and material-intensive FAME preparation methods, such as transmethylation with methanolic HCl. We applied this method to the screening of laboratory and environmental isolates of the green alga Chlamydomonas for variations in fatty acid composition. This screening method facilitated two novel discoveries. First, we identified a common laboratory strain of C. reinhardtii, CC-620, completely lacking all -3 fatty acids normally found in this organism and showed that this strain contains an inactivating mutation in the CrFAD7 gene, encoding the sole -3 desaturase activity in this organism. Second, we showed that some species of Chlamydomonas make ⌬6-unsaturated polyunsaturated fatty acids (PUFA) rather than the ⌬5 species normally made by the previously characterized laboratory strains of Chlamydomonas, suggesting that there is species-specific variation in the regiospecificity and substrate selectivity of front-end desaturases in this algal genus.

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“…Probes were generated by random prime labeling (Prime-It II Cat # 300385, Stratagene, La Jolla, CA, USA). Hybridization parameters, with a dCT32P labeled probes of the HvAlaAT (504 bp) were conducted as described by Eckert et al (2006).…”

Section: Molecular Characterization Of Transgenic Plantsmentioning

confidence: 99%

Molecular and phenotypic characterization of transgenic wheat and sorghum events expressing the barley alanine aminotransferase

Pena

Quach

Sato

et al. 2017

Planta

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Main conclusion -The expression of a barley alanine aminotransferase gene impacts agronomic outcomes in a C3 crop, wheat.The use of nitrogen-based fertilizers has become one of the major agronomic inputs in crop production systems. Strategies to enhance nitrogen assimilation and flux in planta are being pursued through the introduction of novel genetic alleles. Here an Agrobacterium-mediated approach was employed to introduce the alanine aminotransferase from barley (Hordeum vulgare), HvAlaAT, into wheat (Triticum aestivum) and sorghum (Sorghum bicolor), regulated by either constitutive or root preferred promoter elements. Plants harboring the transgenic HvAlaAT alleles displayed increased alanine aminotransferase (alt) activity. The enhanced alt activity impacted height, tillering and significantly boosted vegetative biomass relative to controls in wheat evaluated under hydroponic conditions, where the phenotypic outcome across these parameters varied relative to time of year study was conducted. Constitutive expression of HvAlaAT translated to elevation in wheat grain yield under field conditions. In sorghum, expression of HvAlaAT enhanced enzymatic activity, but no changes in phenotypic outcomes were observed. Taken together these results suggest that positive agronomic outcomes can be achieved through enhanced alt activity in a C3 crop, wheat. However, the variability observed across experiments under greenhouse conditions implies the phenotypic outcomes imparted by the HvAlaAT allele in wheat may be impacted by environment.

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Co-expression of the borage Δ6 desaturase and the Arabidopsis Δ15 desaturase results in high accumulation of stearidonic acid in the seeds of transgenic soybean

Cited by 102 publications

References 32 publications

Identification of bifunctional Δ12/ω3 fatty acid desaturases for improving the ratio of ω3 to ω6 fatty acids in microbes and plants

Identification of bifunctional Δ12/ω3 fatty acid desaturases for improving the ratio of ω3 to ω6 fatty acids in microbes and plants

A High-Throughput Fatty Acid Profiling Screen Reveals Novel Variations in Fatty Acid Biosynthesis in Chlamydomonas reinhardtii and Related Algae

Molecular and phenotypic characterization of transgenic wheat and sorghum events expressing the barley alanine aminotransferase

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