Intron-mediated enhancement of DIACYLGLYCEROL ACYLTRANSFERASE1 expression in energycane promotes a step change for lipid accumulation in vegetative tissues

Biotechnology for Biofuels and Bioproducts

Research

Viet Dang Cao¹  Shelby Korynta¹  Guangbin Luo¹  Fredy Altpeter¹  Hui Liu²  Yuanxue Liang²  John Shanklin³ 

[1] 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;Biology Department, Brookhaven National Laboratory, Upton, NY, USA;DOE Center for Advanced Bioenergy and Bioproducts Innovation, Upton, NY, USA;Biology Department, Brookhaven National Laboratory, Upton, NY, USA;DOE Center for Advanced Bioenergy and Bioproducts Innovation, Upton, NY, USA;Biosciences Department, Brookhaven National Laboratory, Upton, NY, USA;

关键词: Energycane;    WRINKLED;    DIACYLGLYCEROL ACYLTRANSFERASE;    OLEOSIN;    Triacylglycerol;    Metabolic engineering;    Lipids;    Biofuel;    Bioenergy;    Intron-mediated enhancement;    Transgene expression;   

DOI  :  10.1186/s13068-023-02393-1

 received in 2023-07-15, accepted in 2023-09-09,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundMetabolic engineering for hyperaccumulation of lipids in vegetative tissues is a novel strategy for enhancing energy density and biofuel production from biomass crops. Energycane is a prime feedstock for this approach due to its high biomass production and resilience under marginal conditions. DIACYLGLYCEROL ACYLTRANSFERASE (DGAT) catalyzes the last and only committed step in the biosynthesis of triacylglycerol (TAG) and can be a rate-limiting enzyme for the production of TAG.ResultsIn this study, we explored the effect of intron-mediated enhancement (IME) on the expression of DGAT1 and resulting accumulation of TAG and total fatty acid (TFA) in leaf and stem tissues of energycane. To maximize lipid accumulation these evaluations were carried out by co-expressing the lipogenic transcription factor WRINKLED1 (WRI1) and the TAG protect factor oleosin (OLE1). Including an intron in the codon-optimized TmDGAT1 elevated the accumulation of its transcript in leaves by seven times on average based on 5 transgenic lines for each construct. Plants with WRI1 (W), DGAT1 with intron (Di), and OLE1 (O) expression (WDiO) accumulated TAG up to a 3.85% of leaf dry weight (DW), a 192-fold increase compared to non-modified energycane (WT) and a 3.8-fold increase compared to the highest accumulation under the intron-less gene combination (WDO). This corresponded to TFA accumulation of up to 8.4% of leaf dry weight, a 2.8-fold or 6.1-fold increase compared to WDO or WT, respectively. Co-expression of WDiO resulted in stem accumulations of TAG up to 1.14% of DW or TFA up to 2.08% of DW that exceeded WT by 57-fold or 12-fold and WDO more than twofold, respectively. Constitutive expression of these lipogenic “push pull and protect” factors correlated with biomass reduction.ConclusionsIntron-mediated enhancement (IME) of the expression of DGAT resulted in a step change in lipid accumulation of energycane and confirmed that under our experimental conditions it is rate limiting for lipid accumulation. IME should be applied to other lipogenic factors and metabolic engineering strategies. The findings from this study may be valuable in developing a high biomass feedstock for commercial production of lipids and advanced biofuels.Graphical abstract

【 授权许可】

CC BY   
© BioMed Central Ltd., part of Springer Nature 2023

【 图 表 】

Fig. 2

Fig. 6

Fig. 7

Fig. 4

Fig. 2

Fig. 1