Lipid profiling and oil properties of Camelina sativa seeds engineered to enhance the production of saturated and omega-7 fatty acids

Abstract

Camelina sativa is one of the preferred oil crops in plant biotechnology due to its agronomic performance, the quality of its oil and the ease with which it can be transformed. Oils with high levels of saturated fatty acids are in demand for structured lipid elaboration, whereas ω-7 fatty acids like palmitoleic or asclepic acids are of interest for other applications, such as in oleochemistry and biolubricant production. Several strategies have been followed to increase the levels of saturated and ω-7 fatty acids in the camelina plant in this work, including silencing the β-ketoacyl-ACP synthase II (CsKASII) condensing enzyme responsible for the elongation of palmitate to stearate, the expression of exogenous thioesterases, and the overexpression of the endogenous stearoyl-ACP desaturase. The silencing of CsKASII produces an important increase in palmitate in the oil seed, whereas the expression of different alleles of sunflower FatA thioesterases favors the accumulation of both palmitate and stearate. The increase in intraplastidial desaturase activity through CsSAD co-expression forced the desaturation of palmitate, inducing the accumulation of important amounts of ω-7 fatty acids. The phenotypes of the different transformants produced were characterized by profiling the different glycerolipid classes accumulated in their seeds. These oils displayed altered physical properties that were investigated by differential calorimetry studies.