title: Step changes in leaf oil accumulation via iterative metabolic engineering.
abstract: Synthesis and accumulation of plant oils in the entire vegetative biomass offers the potential to deliver yields surpassing those of oilseed crops. However, current levels still fall well short of those typically found in oilseeds. Here we show how transcriptome and biochemical analyses pointed to a futile cycle in a previously established Nicotiana tabacum line, accumulating up to 15% (dry weight) of the storage lipid triacylglycerol in leaf tissue. To overcome this metabolic bottleneck, we either silenced the SDP1 lipase or overexpressed the Arabidopsis thaliana LEC2 transcription factor in this transgenic background. Both strategies independently resulted in the accumulation of 30-33% triacylglycerol in leaf tissues. Our results demonstrate that the combined optimization of de novo fatty acid biosynthesis, storage lipid assembly and lipid turnover in leaf tissue results in a major overhaul of the plant central carbon allocation and lipid metabolism. The resulting further step changes in oil accumulation in the entire plant biomass offers the possibility of delivering yields that outperform current oilseed crops.
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia. Electronic address: Thomas.Vanhercke@csiro.au.
authors.forename: Thomas
authors.initials: T
authors.lastname: Vanhercke
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Uday K
authors.initials: UK
authors.lastname: Divi
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Anna
authors.initials: A
authors.lastname: El Tahchy
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Madeline
authors.initials: M
authors.lastname: Mitchell
authors.affiliation: CSIRO Land and Water, PO Box 1700, Canberra, ACT 2601, Australia.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Taylor
authors.affiliation: Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, United Kingdomna Scholarship Council (CSC.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Eastmond
authors.affiliation: Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, United Kingdomna Scholarship Council (CSC.
authors.forename: Fiona
authors.initials: F
authors.lastname: Bryant
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Anna
authors.initials: A
authors.lastname: Mechanicos
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Blundell
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia; State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhi
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Srinivas
authors.initials: S
authors.lastname: Belide
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Pushkar
authors.initials: P
authors.lastname: Shrestha
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Xue-Rong
authors.initials: XR
authors.lastname: Zhou
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Ral
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Rosemary G
authors.initials: RG
authors.lastname: White
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Allan
authors.initials: A
authors.lastname: Green
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: Surinder P
authors.initials: SP
authors.lastname: Singh
authors.affiliation: CSIRO Agriculture and Food, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: James R
authors.initials: JR
authors.lastname: Petrie
mesh_terms: D017360:Arabidopsis / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics; D024861:Genetic Enhancement / Q000379:methods*; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology*; D010938:Plant Oils / Q000302:isolation & purification / Q000378:metabolism*; D014026:Nicotiana / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C504240:LEC2 protein, Arabidopsis; D010938:Plant Oils; C557635:Spd1 protein, Arabidopsis; D014157:Transcription Factors
keywords: LEC2; Leaf; Nicotiana tabacum; SDP1; Triacylglycerol