TY - JOUR
T1 - Generation of camelina mid-oleic acid seed oil by identification and stacking of fatty acid biosynthetic mutants
AU - Neumann, Nicholas G.
AU - Nazarenus, Tara J.
AU - Aznar-Moreno, Jose A.
AU - Rodriguez-Aponte, Sergio A.
AU - Mejias Veintidos, Valerie A.
AU - Comai, Luca
AU - Durrett, Timothy P.
AU - Cahoon, Edgar B.
N1 - Funding Information:
The research was supported in part by grants from the U.S. Department of Energy , Office of Science , OBER (DOE‐BER SC0012459 to LC, TPD, and EBC) and National Science Foundation Plant Genome Program (award 1444612 to LC and award 1339385 to EBC). We also acknowledge support to SR and VAMV from National Science Foundation Research Experiences for Undergraduates Site: Integrated Development of Bioenergy Systems (award 1560163). Sustainable Oils, Inc. kindly provided access to the Camelina TILLING library screened by the authors under biological material transfer agreements with each of the authors’ universities.
PY - 2021/1
Y1 - 2021/1
N2 - Modifying oilseeds to obtain a desired fatty acid composition is often necessary to enable use as feedstocks for specific applications such as food processing, biofuels, or biolubricants. A mutant population of camelina (Camelina sativa), an emerging specialty oilseed crop, was screened by high-throughput gas chromatography for lines with altered seed oil fatty acid composition. By leveraging knowledge of fatty acid synthesis in Arabidopsis thaliana, mutations in orthologs of FATTY ACID ELONGASE1 (FAE1), FATTY ACID DESATURASE2 (FAD2), FATTY ACID DESATURASE3 (FAD3), and β-KETO-ACYL-ACP SYNTHASE II (KASII; FAB1) were identified. The mutations altered conserved amino acid residues in the encoded proteins. The ability of the mutations in FAE1, FAD2 and FAD3 to affect enzyme function was demonstrated by comparing in vivo activities of wild-type and mutant alleles in yeast. In addition, expression of wild-type cDNA in camelina complemented fatty acid phenotypes of these mutants. As camelina has a hexaploid genome, the effect of a mutation in one of the three homeologs for each gene resulted in no or less severe growth phenotypes compared to similar mutations in Arabidopsis. Mid-oleic oils with nearly 40 % oleic acid and reduced very long-chain (≤C20) fatty acid content were obtained by crossing to obtain a fae1c/fad2a/fae1a/fad3a quadruple mutant. Little effect on total seed oil content was observed in the stacked mutant line. The resulting mid-oleic acid oil had improved oxidative stability due to reductions in polyunsaturated fatty acid content, increasing its utility for biofuels and other applications.
AB - Modifying oilseeds to obtain a desired fatty acid composition is often necessary to enable use as feedstocks for specific applications such as food processing, biofuels, or biolubricants. A mutant population of camelina (Camelina sativa), an emerging specialty oilseed crop, was screened by high-throughput gas chromatography for lines with altered seed oil fatty acid composition. By leveraging knowledge of fatty acid synthesis in Arabidopsis thaliana, mutations in orthologs of FATTY ACID ELONGASE1 (FAE1), FATTY ACID DESATURASE2 (FAD2), FATTY ACID DESATURASE3 (FAD3), and β-KETO-ACYL-ACP SYNTHASE II (KASII; FAB1) were identified. The mutations altered conserved amino acid residues in the encoded proteins. The ability of the mutations in FAE1, FAD2 and FAD3 to affect enzyme function was demonstrated by comparing in vivo activities of wild-type and mutant alleles in yeast. In addition, expression of wild-type cDNA in camelina complemented fatty acid phenotypes of these mutants. As camelina has a hexaploid genome, the effect of a mutation in one of the three homeologs for each gene resulted in no or less severe growth phenotypes compared to similar mutations in Arabidopsis. Mid-oleic oils with nearly 40 % oleic acid and reduced very long-chain (≤C20) fatty acid content were obtained by crossing to obtain a fae1c/fad2a/fae1a/fad3a quadruple mutant. Little effect on total seed oil content was observed in the stacked mutant line. The resulting mid-oleic acid oil had improved oxidative stability due to reductions in polyunsaturated fatty acid content, increasing its utility for biofuels and other applications.
KW - Biofuels
KW - Camelina sativa
KW - Genetic improvement
KW - Vegetable oil
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U2 - 10.1016/j.indcrop.2020.113074
DO - 10.1016/j.indcrop.2020.113074
M3 - Article
AN - SCOPUS:85096194910
VL - 159
JO - Industrial Crops and Products
JF - Industrial Crops and Products
SN - 0926-6690
M1 - 113074
ER -