Recombinant expression of plant diacylglycerol acyltransferases from tissues that accumulate saturated fatty acids

• Author / Creator

  Zhang, Ying

• Vegetable oils enriched in saturated fatty acids (SFAs) could provide solid-fat functionality and decrease our reliance on hydrogenated oils. This thesis focuses on the characterization of enzymes that can preferentially incorporate SFAs into triacylglycerol (TAG). Acyl-CoA:diacylglycerol acyltransferase (DGAT) catalyzes the final reaction in acyl-CoA-dependent TAG biosynthesis, and may have a substantial effect on the flow of carbon into TAG. DGAT cDNAs encoding type-1 or 2 enzymes were isolated from sea buckthorn (Hippophae rhamnoides) pulp and cocoa (Theobroma cacao) beans, both of which contain oils enriched in SFAs. Expression of the HrDGATs or TcDGATs resulted in different ratios of palmitic to stearic acid in the TAG of yeast mutant strain deficient in TAG synthesis. Furthermore, expression of HrDGAT1 in developing seeds of the Arabidopsis DGAT1 knockout mutant restored TAG accumulation and altered the fatty acid composition. These results suggest that HrDGATs or TcDGATs could potentially be used to increase the SFA content of vegetable oils.

• Subjects / Keywords

  • Sea buckthorn pulp
  • cocoa bean
  • diacylglycerol acyltransferases
  • triacylglycerol
  • cloning

• Graduation date

  Spring 2012

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3TD6Q

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.