Title: Towards oilcane: Engineering hyperaccumulation of triacylglycerol into sugarcane stems

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 two-fold 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 in replicated greenhouse experiments by multi-gene engineering. The metabolic engineering included constitutive co-expression of Wrinkled1 (WRI1); Diacylglycerol acyltransferase1-2 (DGAT1-2); Cysteine-oleosin (CYSOLE1); and RNAi-suppression of SUGAR-DEPENDENT1 (SDP1). 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 dry weight and the amount of total fatty acids reached 13% of dry weight. With increasing TAG accumulation an increase of 18:1 unsaturated fatty acids at the expense of 16:0 and 18:0 saturated fatty acids was observed. Total biomass accumulation, soluble lignin, Brix and juice content were significantly reduced in the TAG hyperaccumulating sugarcane lines. Overcoming this yield dragmore » by engineering lipid accumulation into late stem development will be critical to exceed lipid yields of current oilseed crops.« less

Authors:

Parajuli, Saroj  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-9556-4700"
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Kannan, Baskaran  ^[2];

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Karan, Ratna ^[1]; Sanahuja, Georgina ^[1]; Liu, Hui ^[3]; Garcia‐Ruiz, Eva ^[4]; Kumar, Deepak ^[5]; Singh, Vijay  ^[6];

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Zhao, Huimin ^[7]; Long, Stephen  ^[8];

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Shanklin, John  ^[3];

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Altpeter, Fredy  ^[2]

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+ Show Author Affiliations

1. Agronomy Department Plant Molecular and Cellular Biology Program Genetics Institute University of Florida, IFAS Gainesville FL USA
2. Agronomy Department Plant Molecular and Cellular Biology Program Genetics Institute University of Florida, IFAS Gainesville FL USA, DOE Center for Advanced Bioenergy and Bioproducts Innovation Gainesville FL USA
3. DOE Center for Advanced Bioenergy and Bioproducts Innovation Upton NY USA, Biosciences Department Brookhaven National Laboratory Upton NY USA
4. Department of Chemical and Biomolecular Engineering University of Illinois at Urbana‐Champaign Urbana IL USA
5. Department of Agricultural and Biological Engineering University of Illinois at Urbana‐Champaign Urbana IL USA
6. Department of Agricultural and Biological Engineering University of Illinois at Urbana‐Champaign Urbana IL USA, DOE Center for Advanced Bioenergy and Bioproducts Innovation Urbana IL USA
7. Department of Chemical and Biomolecular Engineering University of Illinois at Urbana‐Champaign Urbana IL USA, DOE Center for Advanced Bioenergy and Bioproducts Innovation Urbana IL USA
8. DOE Center for Advanced Bioenergy and Bioproducts Innovation Urbana IL USA, Departments of Plant Biology and Crop Sciences Institute for Genomic Biology University of Illinois at Urbana‐Champaign Urbana IL USA

Publication Date:

2020-05-23

Research Org.:

Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), Urbana, IL (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER)

OSTI Identifier:

1630650

Alternate Identifier(s):

OSTI ID: 1616262; OSTI ID: 1617675; OSTI ID: 1630651

Report Number(s):

BNL-215908-2020-JAAM
Journal ID: ISSN 1757-1693

Grant/Contract Number:  

DE‐AR0000206; DE‐SC0018420; SC0018420; SC0012704

Resource Type:

Published Article

Journal Name:

Global Change Biology. Bioenergy

Additional Journal Information:

Journal Name: Global Change Biology. Bioenergy Journal Volume: 12 Journal Issue: 7; Journal ID: ISSN 1757-1693

Publisher:

Wiley-Blackwell

Country of Publication:

United Kingdom

Language:

English

Subject:

09 BIOMASS FUELS; metabolic engineering, triacylglycerol, sugarcane, biofuel, fatty acids, RNAi; 59 BASIC BIOLOGICAL SCIENCES