@article{079ad8ba8d084d228b34fca33461c012,
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 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.",
keywords = "RNAi, biofuel, fatty acids, metabolic engineering, sugarcane, triacylglycerol",
author = "Saroj Parajuli and Baskaran Kannan and Ratna Karan and Georgina Sanahuja and Hui Liu and Eva Garcia-Ruiz and Deepak Kumar and Vijay Singh and Huimin Zhao and Stephen Long and John Shanklin and Fredy Altpeter",
note = "Funding Information: This research was co-funded by the U.S. Department of Energy (DOE), Advanced Research Projects Award-Energy (ARPA-E), under award number DE-AR0000206 and by the DOE Center for Advanced Bioenergy and Bioproducts Innovation (U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research) under award number DE-SC0018420. Award number DE-AR0000206 supported vector construction, generation of primary transgenic plants and their analysis for transgene integration, transgene expression and lipid accumulation. Award Number DE-SC0018420 supported the analysis of transgenic progeny plants in a replicated greenhouse trial, including transgene expression and lipid accumulation. Any opinions, findings and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the U.S. Department of Energy. This work was also supported by the USDA National Institute of Food and Agriculture, Hatch project 1020425. Confocal microscopy was performed at the Center for Functional Nanomaterials at Brookhaven National Laboratory. The authors would like to thank Dr. Hardev Sandhu, Everglades Research and Education Center, UF-IFAS for providing sugarcane tops and Sun Gro Horticulture, Apopka, FL for the donation of potting mix. The authors have no conflict of interest to declare. Funding Information: This research was co‐funded by the U.S. Department of Energy (DOE), Advanced Research Projects Award‐Energy (ARPA‐E), under award number DE‐AR0000206 and by the DOE Center for Advanced Bioenergy and Bioproducts Innovation (U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research) under award number DE‐SC0018420. Award number DE‐AR0000206 supported vector construction, generation of primary transgenic plants and their analysis for transgene integration, transgene expression and lipid accumulation. Award Number DE‐SC0018420 supported the analysis of transgenic progeny plants in a replicated greenhouse trial, including transgene expression and lipid accumulation. Any opinions, findings and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the U.S. Department of Energy. This work was also supported by the USDA National Institute of Food and Agriculture, Hatch project 1020425. Confocal microscopy was performed at the Center for Functional Nanomaterials at Brookhaven National Laboratory. The authors would like to thank Dr. Hardev Sandhu, Everglades Research and Education Center, UF‐IFAS for providing sugarcane tops and Sun Gro Horticulture, Apopka, FL for the donation of potting mix. The authors have no conflict of interest to declare. Publisher Copyright: {\textcopyright} 2020 The Authors. GCB Bioenergy published by John Wiley & Sons Ltd",
year = "2020",
month = jul,
day = "1",
doi = "10.1111/gcbb.12684",
language = "English (US)",
volume = "12",
pages = "476--490",
journal = "GCB Bioenergy",
issn = "1757-1693",
publisher = "Wiley-VCH",
number = "7",
}