Vernonia DGATs increase accumulation of epoxy fatty acids in oil

Vernolic acid (cis-12-epoxy-octadeca-cis-9-enoic acid) is valuable as a renewable chemical feedstock This fatty acid can accumulate to high levels in the seed oil of some plant species such as Vernonia galamensis and Stokesla laevis which are unsuitable for large-scale production A cost-effective alternative for production of epoxy fatty acids is to genetically engineer its biosynthesis in commercial oilseeds An epoxygenase cDNA (SIEPX) responsible for vernolic acid synthesis and two acyl-CoA diacylglycerol acyltransferase cDNAs (VgDGAT1 and VgDGAT2) catalysing triacylglycerol (TAG) formation were cloned from developing seeds of S laevis and V. galamensis Co-expression of SIEPX and VgDGATI or VgDGAT2 greatly increases accumulation of vernolic acid both in petunia leaves and soybean somatic embryos Seed-specific expression of VgDGAT1 and VgDGAT2 in SIEPX mature soybean seeds results in vernolic acid levels of similar to 15% and 26% Both IDGATI and DGAT2 increase epoxy fatty acid accumulation with DGAT2 having Much greater impact