Overexpression of MYB115, AAD2, or AAD3 in Arabidopsis thaliana seeds yields contrasting omega-7 contents

Omega-7 monoenoic fatty acids (omega-7 FAs) are increasingly exploited both for their positive effects on health and for their industrial potential. Some plant species produce fruits or seeds with high amounts of omega-7 FAs. However, the low yields and poor agronomic properties of these plants preclude their commercial use. As an alternative, the metabolic engineering of oilseed crops for sustainable omega-7 FA production has been proposed. Two palmitoyl-ACP desaturases (PADs) catalyzing omega-7 FA biosynthesis were recently identified and characterized in Arabidopsis thaliana, together with MYB115 and MYB118, two transcription factors that positively control the expression of the corresponding PAD genes. In the present research, we examine the biotechnological potential of these new actors of omega-7 metabolism for the metabolic engineering of plant-based production of omega-7 FAs. We placed the PAD and MYB115 coding sequences under the control of a promoter strongly induced in seeds and evaluated these different constructs in A. thaliana. Seeds were obtained that exhibit omega-7 FA contents ranging from 10 to >50% of the total FAs, and these major compositional changes have no detrimental effect on seed germination.