Title: Generation of camelina mid-oleic acid seed oil by identification and stacking of fatty acid biosynthetic mutants

Abstract

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/fad3amore » quadruple mutant. Little effect on total seed oil content was observed in the stacked mutant line. Finally, 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.« less

Authors:

Neumann, Nicholas G. ^[1]; Nazarenus, Tara J. ^[2]; Aznar-Moreno, Jose A. ^[1]; Rodriguez-Aponte, Sergio A. ^[2]; Mejias Veintidos, Valerie A. ^[2]; Comai, Luca ^[3]; Durrett, Timothy P. ^[1]; Cahoon, Edgar B. ^[2]

---

+ Show Author Affiliations

1. Univ. of Kansas, Lawrence, KS (United States). Dept. of Biochemistry and Molecular Biophysics
2. Univ. of Nebraska, Lincoln, NE (United States). Center for Plant Science Innovation. Dept. of Biochemistry
3. Univ. of California, Davis, CA (United States). Dept. of Plant Biology. Davis Genome Center

Publication Date:

Wed Nov 18 00:00:00 EST 2020

Research Org.:

Colorado State Univ., Fort Collins, CO (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER); National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1851641

Alternate Identifier(s):

OSTI ID: 1809660

Grant/Contract Number:  

SC0012459; 1444612; 1339385; 1560163

Resource Type:

Accepted Manuscript

Journal Name:

Industrial Crops and Products

Additional Journal Information:

Journal Volume: 159; Journal Issue: C; Journal ID: ISSN 0926-6690

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; 09 BIOMASS FUELS; Agriculture; Camelina sativa; Genetic improvement; Vegetable oil; Biofuels