Towards the synthetic design of camelina oil enriched in tailored acetyl-triacylglycerols with medium-chain fatty acids. (6th July 2018)

• Record Type: Journal Article
• Authors: Bansal, Sunil; Kim, Hae Jin; Na, GunNam; Hamilton, Megan E; Cahoon, Edgar B; Lu, Chaofu; Durrett, Timothy P
• Is Part Of: Journal of experimental botany. Volume 69:Number 18(2018)
• Page Start: 4395
• Page End: 4402
• Publication Date: 2018-07-06
• Subjects: Acetyl-TAG -- biofuels -- bioproducts -- Camelina sativa -- medium chain fatty acid -- synthetic biology -- vegetable oil; Botany -- Periodicals; Botany, Experimental -- Periodicals; Plant physiology -- Periodicals; 580
• DOI: 10.1093/jxb/ery225
• Languages: English
• ISSNs: 0022-0957

Abstract

Abstract : Plants of the oilseed crop camelina were metabolically engineered to produce acetyl-triacylglycerol molecules containing medium-chain fatty acids, resulting in tailored lipids with a designed structure that are potentially useful for biofuel and industrial applications. Abstract: The ability to manipulate expression of key biosynthetic enzymes has allowed the development of genetically modified plants that synthesise unusual lipids that are useful for biofuel and industrial applications. By taking advantage of the unique activities of enzymes from different species, tailored lipids with a targeted structure can be conceived. In this study we demonstrate the successful implementation of such an approach by metabolically engineering the oilseed crop Camelina sativa to produce 3-acetyl-1, 2-diacyl- sn -glycerols (acetyl-TAGs) with medium-chain fatty acids (MCFAs). Different transgenic camelina lines that had been genetically modified to produce MCFAs through the expression of MCFA-specific thioesterases and acyltransferases were retransformed with the Euonymus alatus gene for diacylglycerol acetyltransferase (EaDAcT) that synthesises acetyl-TAGs. Concomitant RNAi suppression of acyl-CoA:diacylglycerol acyltransferase increased the levels of acetyl-TAG, with up to 77 mole percent in the best lines. However, the total oil content was reduced. Analysis of the composition of the acetyl-TAG molecular species using electrospray ionisation mass spectrometry demonstrated the successful synthesis of acetyl-TAG containing MCFAs. Field growth of high-yielding plants generated enough oil for quantification of viscosity. As part of an ongoing design–test–learn cycle, these results, which include not only the synthesis of 'designer' lipids but also their functional analysis, will lead to the future production of such molecules tailored for specific applications.