Critical Metabolic Pathways And Genes Cooperate For Epoxy Fatty Acid-Enriched Oil Production In Developing Seeds of Vernonia Galamensis, An Industrial Oleaginous Plant

Background: Vernonia galamensis, originated from Africa, is an annual oleaginous plant of Asteraceae family. As a newly-establishing industrial oil crop, this plant produces high level (> 70%) of vernolic acid (cis-12-epoxyoctadeca-cis-9-enoic acid), an unusual epoxy fatty acid (EFA) with multiple industrial applications. Here, transcriptome analysis and fatty acid profiling from developing V. galamensis seeds were integrated to uncover the critical metabolic pathways responsible for high EFA accumulation and identify the targets that could be used in assembly of EFA biosynthesis pathway in existing oilseed crops. Results: Based on oil accumulation dynamics of V. galamensis seeds, we harvested seed samples from three stages (17, 38, and 45 days after pollination, DAP) representing the initial, fast and final EFA accumulation phases, and one mixed sample from different tissues for RNA-sequencing, with three biological replicates at each sample. Using Illumina platform, we have generated a total of 265 million raw cDNA reads. After filtering process, de novo assembly of clean reads yielded 67,114 unigenes with an N50 length of 1,316 nt. Functional annotation resulted in the identification of almost all genes involved in diverse lipid-metabolic pathways, including the novel fatty acid desaturase/epoxygenase, diacylglycerol acyltransferase 1 and 2, and phospholipid:diacylglycerol acyltransferases. By comparison, we found that various genes associated with acyl editing, fatty acid β-oxidation, triacylglycerol assembly and oil-body formation had greater expression levels at middle developmental stage (38 DAP), which are consistent with the fast accumulation of EFA in V. galamensis developing seed, implying their fundamental roles in EFA production. Additionally, we isolated some transcription factors (such as WRI1, FUS3 and ABI4), which putatively regulated the production of V. galamensis seed oils. The transient assay of selected genes resulted in a synergistic increase of EFA-enriched TAG accumulation in tobacco leaves. Transcriptome data were further confirmed by quantitative real-time PCR for twelve key genes in EFA biosynthesis. Finally, a comprehensive network for high EFA accumulation in V. galamensis seed was established.Conclusions: Our results are of significance with regard to understanding the molecular mechanisms underlying the natural epoxy oil production in this plant and provide valuable reference for developing other oilseeds with high level of valued epoxy oil.

Solvent-free oxidative cleavage of epoxy fatty acid methyl esters by a “release and capture” catalytic system

A green synthesis of bio-aldehydes from vegetable oil derivatives is provided by a WO3/H2O2-based “release and capture” catalytic system.

Recovery from Cogwheel Rigidity and Akinesia and Improvement in Vibration Sense and Olfactory Perception following Removal of an Epoxy-Oleic Acid DNA Adduct

The epoxy fatty acidcis-12,13-epoxy-oleic acid, which acts as a DNA adduct, may be generated during long-term storage of many seed oils, including those used in cooking, with frying oils and fried foods being a major source in the modern human diet. Removal of this epoxy fatty acid from the locus of theN-formyl peptide receptors was associated with recovery from cogwheel rigidity and akinesia as well as with improvement in vibration sense and olfactory perception.