title: The sugar-dependent1 lipase limits triacylglycerol accumulation in vegetative tissues of Arabidopsis.
abstract: There has been considerable interest recently in the prospect of engineering crops to produce triacylglycerol (TAG) in their vegetative tissues as a means to achieve a step change in oil yield. Here, we show that disruption of TAG hydrolysis in the Arabidopsis (Arabidopsis thaliana) lipase mutant sugar-dependent1 (sdp1) leads to a substantial accumulation of TAG in roots and stems but comparatively much lower TAG accumulation in leaves. TAG content in sdp1 roots increases with the age of the plant and can reach more than 1% of dry weight at maturity, a 50-fold increase over the wild type. TAG accumulation in sdp1 roots requires both ACYL-COENZYME A:DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1) and PHOSPHATIDYLCHOLINE:DIACYLGLYCEROL ACYLTRANSFERASE1 and can also be strongly stimulated by the provision of exogenous sugar. In transgenic plants constitutively coexpressing WRINKLED1 and DGAT1, sdp1 also doubles the accumulation of TAG in roots, stems, and leaves, with levels ranging from 5% to 8% of dry weight. Finally, provision of 3% (w/v) exogenous Suc can further boost root TAG content in these transgenic plants to 17% of dry weight. This level of TAG is similar to seed tissues in many plant species and establishes the efficacy of an engineering strategy to produce oil in vegetative tissues that involves simultaneous manipulation of carbohydrate supply, fatty acid synthesis, TAG synthesis, and also TAG breakdown.
authors.affiliation: School of Life Sciences, University of Warwick, Coventry, Warwickshire CV4 7AL, United Kingdom.
authors.forename: Amélie A
authors.initials: AA
authors.lastname: Kelly
authors.forename: Harrie
authors.initials: H
authors.lastname: van Erp
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Quettier
authors.forename: Eve
authors.initials: E
authors.lastname: Shaw
authors.forename: Guillaume
authors.initials: G
authors.lastname: Menard
authors.forename: Smita
authors.initials: S
authors.lastname: Kurup
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Eastmond
mesh_terms: D000217:Acyltransferases / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism*; D051048:Diacylglycerol O-Acyltransferase / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010938:Plant Oils / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D013395:Sucrose / Q000378:metabolism / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014280:Triglycerides / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D010938:Plant Oils; D014157:Transcription Factors; D014280:Triglycerides; C495665:WRINKLED1 protein, Arabidopsis; D013395:Sucrose; D000217:Acyltransferases; C426836:phospholipid diacylglycerol acyltransferase; C579477:DGAT1 protein, Arabidopsis; D051048:Diacylglycerol O-Acyltransferase; D002265:Carboxylic Ester Hydrolases; C510423:SDP1 protein, Arabidopsis