title: Altered lipid composition and enhanced nutritional value of Arabidopsis leaves following introduction of an algal diacylglycerol acyltransferase 2.
abstract: Enhancement of acyl-CoA-dependent triacylglycerol (TAG) synthesis in vegetative tissues is widely discussed as a potential avenue to increase the energy density of crops. Here, we report the identification and characterization of Chlamydomonas reinhardtii diacylglycerol acyltransferase type two (DGTT) enzymes and use DGTT2 to alter acyl carbon partitioning in plant vegetative tissues. This enzyme can accept a broad range of acyl-CoA substrates, allowing us to interrogate different acyl pools in transgenic plants. Expression of DGTT2 in Arabidopsis thaliana increased leaf TAG content, with some molecular species containing very-long-chain fatty acids. The acyl compositions of sphingolipids and surface waxes were altered, and cutin was decreased. The increased carbon partitioning into TAGs in the leaves of DGTT2-expressing lines had little effect on transcripts of the sphingolipid/wax/cutin pathway, suggesting that the supply of acyl groups for the assembly of these lipids is not transcriptionally adjusted. Caterpillars of the generalist herbivore Spodoptera exigua reared on transgenic plants gained more weight. Thus, the nutritional value and/or energy density of the transgenic lines was increased by ectopic expression of DGTT2 and acyl groups were diverted from different pools into TAGs, demonstrating the interconnectivity of acyl metabolism in leaves.
authors: Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA.
authors: Sanjaya
authors: Rachel
authors: R
authors: Miller
authors: Timothy P
authors: TP
authors: Durrett
authors: Dylan K
authors: DK
authors: Kosma
authors: Todd A
authors: TA
authors: Lydic
authors: Bagyalakshmi
authors: B
authors: Muthan
authors: Abraham J K
authors: AJ
authors: Koo
authors: Yury V
authors: YV
authors: Bukhman
authors: Gavin E
authors: GE
authors: Reid
authors: Gregg A
authors: GA
authors: Howe
authors: John
authors: J
authors: Ohlrogge
authors: Christoph
authors: C
authors: Benning
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism; D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D016825:Chlamydomonas reinhardtii / Q000201:enzymology* / Q000235:genetics; D051048:Diacylglycerol O-Acyltransferase / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism; D060434:Herbivory; D050356:Lipid Metabolism / Q000235:genetics; D008055:Lipids / Q000737:chemistry*; D008563:Membrane Lipids / Q000235:genetics / Q000378:metabolism; D009753:Nutritive Value; D010802:Phylogeny; D018515:Plant Leaves / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000254:growth & development; D013107:Sphingolipids / Q000737:chemistry / Q000378:metabolism; D018411:Spodoptera / Q000502:physiology; D014280:Triglycerides / Q000378:metabolism; D014885:Waxes / Q000378:metabolism; D015003:Yeasts / Q000235:genetics
chemical_list: D000214:Acyl Coenzyme A; D005227:Fatty Acids; D008055:Lipids; D008563:Membrane Lipids; D011994:Recombinant Proteins; D013107:Sphingolipids; D014280:Triglycerides; D014885:Waxes; C000521:cutin; D051048:Diacylglycerol O-Acyltransferase