Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract only
Publication Acceptance Date: 3/8/2005
Publication Date: 5/1/2005
Citation: He, X., Chen, G.Q., Lin, J.T., Mckeon, T.A. 2005. Effect of diacylglycerol acyltransferase on lipid metabolism in developing seeds of castor. Annual Meeting and Expo of the American Oil Chemists' Society. Interpretive Summary: In order to find new uses for vegetable oils in surplus, it is essential to develop alternative uses for them. One approach is to biochemically convert the oil to more valuable products. This paper reports the effect of diacylglycerol acyltransferase on lipid metabolism in developing seeds of castor. Castor oil is a vegetable oil with numerous industrial applications, including bio-based plastics, lubricants, bio-fuel additives and coatings. Currently, the domestic market consumes 110 million pounds of this strategically important oil, and it is all imported. The elucidation of this gene’s regulation supports development of biochemical means to produce alternative sources of castor oil. Ultimately, this research will result in domestic capability for castor oil production, expanding the availability of bio-based products.
Technical Abstract: We have previously reported the cloning of castor diacylglycerol acyltransferase (RcDGAT) based on its homology to other plant type 1 DGATs. In order to elucidate the physiological role of the RcDGAT, we have examined the effect of RcDGAT on lipid metabolism during seed development of castor. The RcDGAT expression was demonstrated to be regulated at a posttranscriptional level, the accumulation of transcript greatly precedes detectable translation. RcDGAT activity and its effect on the rate of triacylglycerol (TG) accumulation depended primary on the levels of RcDGAT protein. A dramatic increase of TG and decrease of PC and PE were observed in seeds from 19 to 26 days after pollination (DAP). The major increase of the relative amount of triricinolein in oil was also found at this period of time. These noticeable changes in oil content and composition closely correlated with the increase of RcDGAT protein and activity.