title: Metabolic control analysis is helpful for informed genetic manipulation of oilseed rape (Brassica napus) to increase seed oil content.
abstract: Top-down control analysis (TDCA) is a useful tool for quantifying constraints on metabolic pathways that might be overcome by biotechnological approaches. Previous studies on lipid accumulation in oilseed rape have suggested that diacylglycerol acyltransferase (DGAT), which catalyses the final step in seed oil biosynthesis, might be an effective target for enhancing seed oil content. Here, increased seed oil content, increased DGAT activity, and reduced substrate:product ratio are demonstrated, as well as reduced flux control by complex lipid assembly, as determined by TDCA in Brassica napus (canola) lines which overexpress the gene encoding type-1 DGAT. Lines overexpressing DGAT1 also exhibited considerably enhanced seed oil content under drought conditions. These results support the use of TDCA in guiding the rational selection of molecular targets for oilseed modification. The most effective lines had a seed oil increase of 14%. Moreover, overexpression of DGAT1 under drought conditions reduced this environmental penalty on seed oil content.
authors.affiliation: Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5.
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Weselake
authors.forename: Saleh
authors.initials: S
authors.lastname: Shah
authors.forename: Mingguo
authors.initials: M
authors.lastname: Tang
authors.forename: Patti A
authors.initials: PA
authors.lastname: Quant
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Snyder
authors.forename: Tara L
authors.initials: TL
authors.lastname: Furukawa-Stoffer
authors.forename: Weiming
authors.initials: W
authors.lastname: Zhu
authors.forename: David C
authors.initials: DC
authors.lastname: Taylor
authors.forename: Jitao
authors.initials: J
authors.lastname: Zou
authors.forename: Arvind
authors.initials: A
authors.lastname: Kumar
authors.forename: Linda
authors.initials: L
authors.lastname: Hall
authors.forename: Andre
authors.initials: A
authors.lastname: Laroche
authors.forename: Gerhard
authors.initials: G
authors.lastname: Rakow
authors.forename: Phillip
authors.initials: P
authors.lastname: Raney
authors.forename: Maurice M
authors.initials: MM
authors.lastname: Moloney
authors.forename: John L
authors.initials: JL
authors.lastname: Harwood
mesh_terms: D029688:Brassica napus / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D051048:Diacylglycerol O-Acyltransferase / Q000235:genetics / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D010938:Plant Oils / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*
chemical_list: D010938:Plant Oils; D010940:Plant Proteins; D051048:Diacylglycerol O-Acyltransferase