title: Expression of Mouse MGAT in Arabidopsis Results in Increased Lipid Accumulation in Seeds.
abstract: Worldwide demand for vegetable oil is projected to double within the next 30 years due to increasing food, fuel, and industrial requirements. There is therefore great interest in metabolic engineering strategies that boost oil accumulation in plant tissues, however, efforts to date have only achieved levels of storage lipid accumulation in plant tissues far below the benchmark to meet demand. Monoacylglycerol acyltransferase (MGAT) is predominantly associated with lipid absorption and resynthesis in the animal intestine where it catalyzes monoacylglycerol (MAG) to form diacylglycerol (DAG), and then triacylglycerol (TAG). In contrast plant lipid biosynthesis routes do not include MGAT. Rather, DAG and TAG are either synthesized from glycerol-3-phosphate by a series of three subsequent acylation reactions, or originated from phospholipids via an acyl editing pathway. Mouse MGATs 1 and 2 have been shown to increase oil content transiently in Nicotiana benthamiana leaf tissue by 2.6 fold. Here we explore the feasibility of this approach to increase TAG in Arabidopsis thaliana seed. The stable MGAT2 expression resulted in a significant increase in seed oil content by 1.32 fold. We also report evidence of the MGAT2 activity based on in vitro assays. Up to 3.9 fold increase of radiolabeled DAG were produced in seed lysate which suggest that the transgenic MGAT activity can result in DAG re-synthesis by salvaging the MAG product of lipid breakdown. The expression of MGAT2 therefore creates an independent and complementary TAG biosynthesis route to the endogenous Kennedy pathway and other glycerolipid synthesis routes.
authors.affiliation: CSIRO Agriculture, Canberra, ACTAustralia; CSIRO Food and Nutrition, Canberra, ACTAustralia.
authors.forename: Anna
authors.initials: A
authors.lastname: El Tahchy
authors.affiliation: CSIRO Agriculture, Canberra, ACTAustralia; CSIRO Food and Nutrition, Canberra, ACTAustralia.
authors.forename: James R
authors.initials: JR
authors.lastname: Petrie
authors.affiliation: CSIRO Agriculture, Canberra, ACTAustralia; CSIRO Food and Nutrition, Canberra, ACTAustralia.
authors.forename: Pushkar
authors.initials: P
authors.lastname: Shrestha
authors.affiliation: CSIRO Agriculture, Canberra, ACTAustralia; CSIRO Food and Nutrition, Canberra, ACTAustralia.
authors.forename: Thomas
authors.initials: T
authors.lastname: Vanhercke
authors.affiliation: CSIRO Agriculture, Canberra, ACTAustralia; CSIRO Food and Nutrition, Canberra, ACTAustralia.
authors.forename: Surinder P
authors.initials: SP
authors.lastname: Singh
keywords: Arabidopsis thaliana; acyltransferase; diacylglycerol; gene expression; monoacylglycerol acyltransferase (MGAT); seed oil increase; triacylglycerol biosynthesis
references.citation: Plant Physiol. 2013 Jun;162(2):626-39
references.pmid: 23616604
references.citation: J Biol Chem. 2012 Jan 13;287(3):1946-54
references.pmid: 22128159
references.citation: J Biol Chem. 2003 Apr 18;278(16):13860-6
references.pmid: 12576479
references.citation: FEBS Lett. 2013 Feb 14;587(4):364-9
references.pmid: 23313251
references.citation: FEBS Lett. 2005 Nov 7;579(27):6067-73
references.pmid: 16226259
references.citation: Fed Proc. 1961 Dec;20:934-40
references.pmid: 14455159
references.citation: Plant Physiol Biochem. 2009 Jun;47(6):485-90
references.pmid: 19136267
references.citation: Plant Cell. 1997 Jun;9(6):909-23
references.pmid: 9212466
references.citation: Cell Metab. 2005 May;1(5):323-30
references.pmid: 16054079
references.citation: Plant J. 1998 Dec;16(6):735-43
references.pmid: 10069079
references.citation: PLoS One. 2012;7(4):e35214
references.pmid: 22523576
references.citation: Plant Physiol. 2014 May;165(1):30-6
references.pmid: 24696520
references.citation: Curr Opin Plant Biol. 2003 Apr;6(2):178-84
references.pmid: 12667876
references.citation: Arabidopsis Book. 2010;8:e0133
references.pmid: 22303259
references.citation: Plant Physiol. 2012 Nov;160(3):1530-9
references.pmid: 22932756
references.citation: Proc Natl Acad Sci U S A. 2002 Jun 25;99(13):8512-7
references.pmid: 12077311
references.citation: Plant Physiol. 2009 May;150(1):55-72
references.pmid: 19329563
references.citation: J Exp Bot. 2004 Oct;55(406):2291-303
references.pmid: 15361535
references.citation: Biochim Biophys Acta. 2010 Apr;1801(4):455-61
references.pmid: 20045079
references.citation: Plant Physiol. 2008 Sep;148(1):89-96
references.pmid: 18633120
references.citation: J Biol Chem. 2006 Jan 6;281(1):491-500
references.pmid: 16267052
references.citation: Plant J. 2004 Nov;40(4):575-85
references.pmid: 15500472
references.citation: Front Plant Sci. 2014 May 26;5:204
references.pmid: 24904604
references.citation: J Exp Bot. 2008;59(13):3543-9
references.pmid: 18703491
references.citation: Biotechnol Biofuels. 2014 Mar 08;7(1):36
references.pmid: 24606605
references.citation: J Lipid Res. 2007 Mar;48(3):583-91
references.pmid: 17170429
references.citation: Curr Opin Plant Biol. 2013 Jun;16(3):358-64
references.pmid: 23529069
references.citation: J Clin Invest. 1967 Nov;46(11):1695-703
references.pmid: 6061744
references.citation: J Biol Chem. 2007 Oct 26;282(43):31206-16
references.pmid: 17728247
references.citation: Plant Cell. 2006 Mar;18(3):665-75
references.pmid: 16473965
references.citation: Plant Physiol. 2011 Oct;157(2):866-75
references.pmid: 21825108
references.citation: Proc Natl Acad Sci U S A. 2010 Jun 29;107(26):12040-5
references.pmid: 20551224
references.citation: Can J Biochem Physiol. 1959 Aug;37(8):911-7
references.pmid: 13671378
references.citation: J Exp Bot. 2005 May;56(415):1285-96
references.pmid: 15767324
references.citation: Plant Cell. 2013 Sep;25(9):3506-18
references.pmid: 24076979
references.citation: Plant Physiol. 2013 Jul;162(3):1282-9
references.pmid: 23686420
references.citation: Science. 2004 Nov 19;306(5700):1383-6
references.pmid: 15550674
references.citation: Plant Biotechnol J. 2013 Apr;11(3):355-61
references.pmid: 23171303
references.citation: Plant Physiol. 2000 Mar;122(3):767-74
references.pmid: 10712540
references.citation: Planta. 1975 Jan;123(2):163-74
references.pmid: 24435083
references.citation: Plant Physiol. 1997 Jan;113(1):75-81
references.pmid: 9008389
references.citation: Proc Natl Acad Sci U S A. 2009 Nov 3;106(44):18837-42
references.pmid: 19833868
references.citation: Nat Genet. 2008 Mar;40(3):367-72
references.pmid: 18278045
references.citation: Plant Biotechnol J. 2007 May;5(3):431-41
references.pmid: 17430545
references.citation: J Biol Chem. 2011 Dec 23;286(51):43644-50
references.pmid: 22041902
references.citation: Plant Physiol. 2001 Jun;126(2):861-74
references.pmid: 11402213