Metabolic engineering of oilseed crops to produce high levels of novel acetyl glyceride oils with reduced viscosity, freezing point and calorific value

Journal Article · Tue Mar 10 00:00:00 EDT 2015 · Plant Biotechnology Journal

DOI:https://doi.org/10.1111/pbi.12325· OSTI ID:1400911

Liu, Jinjie ^[1]; Rice, Adam ^[1]; McGlew, Kathleen ^[1]; Shaw, Vincent ^[1]; Park, Hyunwoo ^[2]; Clemente, Tom ^[2]; Pollard, Mike ^[1]; Ohlrogge, John ^[1]; Durrett, Timothy P. ^[3]

---

1. Department of Plant Biology, and Great Lakes Bioenergy Research Center Michigan State University East Lansing MI USA
2. Department of Agronomy and Horticulture University of Nebraska‐Lincoln Lincoln NE USA
3. Department of Biochemistry and Molecular Biophysics Kansas State University Manhattan KS USA

Summary Seed oils have proved recalcitrant to modification for the production of industrially useful lipids. Here, we demonstrate the successful metabolic engineering and subsequent field production of an oilseed crop with the highest accumulation of unusual oil achieved so far in transgenic plants. Previously, expression of the E uonymus alatus diacylglycerol acetyltransferase ( E a DA c T ) gene in wild‐type A rabidopsis seeds resulted in the accumulation of 45 mol% of unusual 3‐acetyl‐1,2‐diacyl‐ sn ‐glycerols (acetyl‐ TAG s) in the seed oil (Durrett et al ., 2010 PNAS 107:9464). Expression of E a DA c T in dgat1 mutants compromised in their ability to synthesize regular triacylglycerols increased acetyl‐ TAG s to 65 mol%. Camelina and soybean transformed with the E a DA c T gene accumulate acetyl‐triacylglycerols (acetyl‐ TAG s) at up to 70 mol% of seed oil. A similar strategy of coexpression of E a DA c T together with RNA i suppression of DGAT 1 increased acetyl‐ TAG levels to up to 85 mol% in field‐grown transgenic C amelina. Additionally, total moles of triacylglycerol ( TAG ) per seed increased 20%. Analysis of the acetyl‐ TAG fraction revealed a twofold reduction in very long chain fatty acids ( VLCFA ), consistent with their displacement from the sn ‐3 position by acetate. Seed germination remained high, and seedlings were able to metabolize the stored acetyl‐ TAG s as rapidly as regular triacylglycerols. Viscosity, freezing point and caloric content of the C amelina acetyl‐ TAG oils were reduced, enabling use of this oil in several nonfood and food applications.

• Sponsoring Organization: USDOE
• OSTI ID: 1400911
• Journal Information: Plant Biotechnology Journal, Journal Name: Plant Biotechnology Journal Vol. 13 Journal Issue: 6; ISSN 1467-7644
• Publisher: Wiley-Blackwell
• Country of Publication: United Kingdom
• Language: English