Towards oilcane: Engineering hyperaccumulation of triacylglycerol into sugarcane stems

GCB Bioenergy

卷:12

Baskaran Kannan¹  Fredy Altpeter¹  Georgina Sanahuja¹  Saroj Parajuli¹  Ratna Karan¹  John Shanklin²  Hui Liu²  Stephen Long³  Vijay Singh⁴  Deepak Kumar⁴  Huimin Zhao⁵  Eva Garcia‐Ruiz⁵ 

[1] Agronomy Department Plant Molecular and Cellular Biology Program Genetics Institute University of Florida, IFAS Gainesville FL USA;

[2] DOE Center for Advanced Bioenergy and Bioproducts Innovation Upton NY USA;

[3] DOE Center for Advanced Bioenergy and Bioproducts Innovation Urbana IL USA;

[4] Department of Agricultural and Biological Engineering University of Illinois at Urbana‐Champaign Urbana IL USA;

[5] Department of Chemical and Biomolecular Engineering University of Illinois at Urbana‐Champaign Urbana IL USA;

关键词: biofuel;    fatty acids;    metabolic engineering;    RNAi;    sugarcane;    triacylglycerol;   

DOI  :  10.1111/gcbb.12684

来源: DOAJ

【 摘 要 】

Abstract Metabolic engineering to divert carbon flux from sucrose to oil in high biomass crop like sugarcane is an emerging strategy to boost lipid yields per hectare for biodiesel production. Sugarcane stems comprise more than 70% of the crops' biomass and can accumulate sucrose in excess of 20% of their extracted juice. The energy content of oils in the form of triacylglycerol (TAG) is more than twofold that of carbohydrates. Here, we report a step change in TAG accumulation in sugarcane stem tissues achieving an average of 4.3% of their dry weight (DW) in replicated greenhouse experiments by multigene engineering. The metabolic engineering included constitutive co‐expression of wrinkled1; diacylglycerol acyltransferase1‐2; cysteine‐oleosin; and ribonucleic acid interference‐suppression of sugar‐dependent1. The TAG content in leaf tissue was also elevated by more than 400‐fold compared to non‐engineered sugarcane to an average of 8.0% of the DW and the amount of total fatty acids reached about 13% of the DW. With increasing TAG accumulation an increase of 18:1 unsaturated fatty acids was observed at the expense of 16:0 and 18:0 saturated fatty acids. Total biomass accumulation, soluble lignin, Brix and juice content were significantly reduced in the TAG hyperaccumulating sugarcane lines. Overcoming this yield drag by engineering lipid accumulation into late stem development will be critical to exceed lipid yields of current oilseed crops.

【 授权许可】

Unknown