Targeted mutagenesis of FATTY ACID ELONGASE 1 entails near complete elimination of very long chain fatty acids in the seeds of camelina cultivar Ligena

TL;DR

Scientists used genome editing to eliminate very long chain fatty acids in camelina seeds, improving their nutritional value.

Contribution

Targeted mutagenesis of FAE1 gene in Camelina sativa leads to high-value fatty acid profile improvement.

Findings

Triple-homozygous fae1 knockout mutants were successfully generated in Camelina Ligena.

Mutagenesis significantly increased unsaturated C18 fatty acids like α-linolenic acid.

Very long-chain fatty acids, including erucic acid, were nearly eliminated in M4 seeds.

Abstract

Genome editing has the potential to enhance yield and quality traits of crops. However, standard genetic transformation methods are not always applicable to modern germplasm. To tackle this challenge in the widely cultivated variety Ligena of the oilseed crop camelina (Camelina sativa (L.) Crantz), an only recently established principle of adventitious shoot formation from immature zygotic embryos was employed to further improve its fatty acid profile. In this approach, the three subgenomic homeologs of the FATTY ACID ELONGASE 1 (FAE1) gene were subjected to targeted mutagenesis. To pre-validate the Cas9-interacting, target motif-specific guide (g)RNAs, a robust protoplast-based DNA transfection method was established. This assay demonstrated that the preselected gRNAs were capable of eliciting mutations across all three camelina FAE1 homeologs. Likewise, targeted mutagenesis was successful at the whole-plant level. Triple-homozygous fae1 knockout mutants were identified amongst a segregating generation M3 family. Gas chromatography of lipid extracts from M4 seeds revealed a significant increase in all unsaturated C18 fatty acids including the particularly valuable α-linolenic acid. This was accompanied by a near elimination of the C20 and C22 very long-chain fatty acids including the nutritionally problematic erucic acid. Altogether, we have developed camelina elite lines with two significantly improved properties of high relevance for a health-promoting human nutrition.

The online version contains supplementary material available at 10.1007/s42994-025-00238-z.

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