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Plant oils, one of the worlds most important renewable oil resources, are widely consumed as food while also having value as renewable chemicals and fuels, such as biodiesel.As plant oils are a critical renewable resource, increasing the production of plant oils and valuable lipid compounds in industry has been a major research field for scientists from both scientific and industry communities.Our lab developed a systematic metabolic pathway assembly platform of plant lipids/oils and successfully obtained the desirable product from the engineered soybean seed oils and the green tissues/organs of tobacco, a non-food crop with a huge amount of inexpensive biomass.Of the four main oil crops: palm, soybean, rapeseed (including canola) and sunflower, soybean has the lowest oil content (20%) and per land oil yield but the highest protein content (40%) and protein yield.However, a negative linkage exists between oil and protein levels in soybean.We isolated a cDNA clone encoding acyl-CoA: diacylglycerol acyltransferase (DGAT) from Vernonia galamensis(VgDGAT), which controls the final step for triacylglycerides (TAGs) biosynthesis.Seed-specific expression of this highly active VgDGAT resulted in the increasing of oil level by 3.5-6.5 % in soybean seeds without reductions in seed protein contents or yield per unit land area.The controlled-expression of VgDGAT also led to the enhancement of oil contents in leaves and stems of tobacco by 7.9-10.4 folds and no other phenotypic changes compared to the WT controls, indicating a possibility of tobacco vegetative organs could be engineered for oil production.ω-7 fatty acids, absent in oilseeds but present in some wild plants, include palmitoleic acid (16∶1 n-7) and its elongated products vaccenic acid (18∶1 n-7) and eicosenoic acid (20∶1 n-7), which are important contributors to human health, and highly valued in pharmaceutical and industry.Moreover, they are the desirable lipid sources for the production of high-quality biodiesel with much strong oxidative stability and cold tolerance.ω-7 fatty acids are also the unique feedstock for producing industrially important and high-demanded 1-octene.An integrative metabolic engineering approach was developed to assembly the related pathway for high synthesis and accumulation of ω-7 fatty acids in seeds and green organs.This strategy include co-overexpression of both cytosolic and plastid C 16 specific n-7 fatty acid desaturase genes from high accumulator of ω-7 fatty acids, RNA interference (RNAi) suppression of FatB C16-ACP thioesterase genes, and blocking activity of the enzyme responsible for oil breakdown.When seed-specific co-expression of those constructs in soybean,ω-7 fatty acid totally accumulated up to 49% in the seed oil, higher than the level in macadamia (Macadamia integrifolia) seed, a naturallyω-7 fatty acid source plant.To explore huge biomass of tobacco for high-quality biodiesel production, the same engineering approach was employed to set upω-7 fatty acid biosynthesis pathway in green tissues/organs of tobacco.Compared to the wild-type tobacco where no ω-7 fatty acids were produced, the transgenic tobacco plants synthesized and accumulatedω-7 fatty acids up to 42% in leaves and stems.In order to commercially produce these unusual fatty acids (UFAs), we then further increased oil content in tobacco green tissues by controlled-expression of a master transcriptional factor WRI1 and combined to over-expressing a key enzyme VgDGAT in oil synthesis pathway.Notably, the transgenic tobacco plants with oil enhancement by 15.3-20.6 folds in leaves and stems were obtained, showing no significant changes in growth and development as well as other agronomic phenotypes.Combination of the approaches described above will have the potential to generate the transgenic tobacco that accumulate both high oil andω-7 fatty acids in the vegetable organs, which will benefit the commercial production of high-quality biodiesel and large-needed 1-octene.Taken together, our findings provide new insights into further understanding of UFA biosynthesis and oil accumulation, indicating that altering the enzymatic machinery of plant oil by gene modifying the enzymes plus master transcriptional factors will be a key to successful metabolic engineering for sustainable production of renewable oils and industrial-valued lipids in any established oilseeds.This systematic metabolic engineering strategy also works well in the vegetable organs of non-food tobacco plants, showing promising in breeding of new type energy plant for commercial production of value-added oils.