A Vernonia Diacylglycerol Acyltransferase Can Increase Renewable Oil Production

Abstract

Increasing the production of plant oils such as soybean oil as a renewable resource for food and fuel is valuable. Successful breeding for higher oil levels in soybean, however, usually results in reduced protein, a second valuable seed component. This study shows that by manipulating a highly active acyl-CoA:diacylglycerol acyltransferase (DGAT) the hydrocarbon flux to oil in oilseeds can be increased without reducing the protein component. Compared to other plant DGATs, a DGAT from Vernonia galamensis (VgDGAT1A) produces much higher oil synthesis and accumulation activity in yeast, insect cells, and soybean. Soybean lines expressing VgDGAT1A show a 4% increase in oil content without reductions in seed protein contents or yield per unit land area. Incorporation of this trait into 50% of soybeans worldwide could result in an increase of 850 million kg oil/year without new land use or inputs and be worth ∼U.S.$1 billion/year at 2012 production and market prices.

Properties and Biotechnological Applications of Acyl‐CoA:diacylglycerol Acyltransferase and Phospholipid:diacylglycerol Acyltransferase from Terrestrial Plants and Microalgae

“…The overexpression of T. majus DGAT1 in Arabidopsis, high‐erucic‐acid rapeseed, and canola‐type B. napus also led to enhanced seed oil content (Xu et al, ). Following these aforementioned studies, many groups have further used DGAT1 from different species to boost seed content in various crops such as G. max (Hatanaka et al, ; Roesler et al, ), B. juncea (Savadi et al, ), Z. mays (Alameldin et al, ), C. sativa (Kim et al, ), and Jatropa curcas (Maravi et al, ). Moreover, overexpression of DGAT1 from microalgae, such as Chlorella ellipsoidea and Nannochloropsis oceanica , also led to increased oil content in Arabidopsis and B. napus (Guo et al, ; Zienkiewicz et al, ).…”

Different DGAT1s show different TAG synthesis abilities and a specific amino acid substitution enhances oil accumulation

“…In our previous study, in a microsome assay using an expression system in wild-type yeast (Saccharomyces cerevisiae), Vernonia DGAT1 showed about 40 times more active than Arabidpsis DGAT1 and about 9 times more active than soybean (Glycine max) DGAT1 (Hatanaka et al, 2016). However, in this system using wild-type yeast, the activity of A. thaliana DGAT1 was close to that of the vector control.…”

Generation and Characterization of a Soybean Line with a Vernonia galamensis Diacylglycerol Acyltransferase‐1 Gene and a myo‐Inositol 1‐Phosphate Synthase Knockout Mutation

“…The temperature program ran from 90 to 250 C with a 25 C ramp for a total of 8 min run time with a constant column flow mode of 0.9 mL/min utilizing a splitless injection. Quantification was performed using a flame ionization detector and peaks quantified using Star Chromatography Workstation Version 6.00 (Varian Inc.) with peak area being used to calculate relative percentages of FAME (Hatanaka et al, 2016).…”

“…This approach has been done successfully by manipulating a highly active acyl‐CoA: diacylglycerol acyltransferase (DGAT) hydrocarbon flux to oil in oilseeds, without reducing protein component. In comparison to other plant DGAT, a DGAT1 from Vernonia galamensis (VgDGAT1A) results in higher oil accumulation activity in soybean seeds and other organisms including yeast (Hatanaka et al, 2016). Soybean lines expressing VgDGAT1A shows a 4% increase in oil content without a reduction in seed protein content or yield per unit land area (Hatanaka et al, 2016).…”