Simultaneous Targeting of Multiple Gene Homeologs to Alter Oil Production in Camelina

Camelina sativa can easily be genetically modified using enzymes from other plants, making it an ideal platform for the production of unusual valuable lipids. However, suppression of endogenous enzyme activity to reduce competition for substrates, such as triacylglycerol, is also required to enhance the production of target compounds. Furthermore, camelina possesses a hexaploid genome, with multiple gene homeologs coding for an enzyme.

Kansas State University researchers designed a guide RNA identical to all three CsDGAT1 or CsPDAT1 homeologs, to demonstrate the ability of the system in introducing mutations to the genes important for triacylglycerol (TAG) synthesis in developing seeds. Analysis from the edited T₁ plants revealed that each CsDGAT1 or CsPDAT1 homeolog was altered by multiple mutations, resulting in a genetic mosaic in the plants.

Seeds harvested from both CsDGAT1- and CsPDAT1-targeted lines were often shrunken and wrinkled. Furthermore, lipid analysis revealed that many lines produced seed with reduced oil content and altered fatty acid composition, consistent with the role of the targeted genes.

CRISPR-Cas system therefore represents a useful method to alter endogenous biosynthetic pathways efficiently in polyploid species such as camelina.

For more on this study, read the article in Plant and Cell Physiology.