Submitted to: American Journal of Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2014
Publication Date: 11/21/2014
Citation: Ponciano, G.P., Chen, G.Q. 2014. Identification of a 3-hydroxy-3-methylglutaryl-CoA reductase gene highly expressed in the root tissue of Taraxacum kok-saghyz. American Journal of Plant Sciences. 5:3603-3608.
Interpretive Summary: The rubber-producing plant, Kazak dandelion (formally Russian dandelion) (Taraxacum kok-saghyz, Tk) is currently being developed as a new crop source for natural rubber. One strategy for increasing dandelion rubber content is to increase the levels of key regulatory enzymes in rubber biosynthesis. One such enzyme is HMGR (3-hydroxy-3-methylglutaryl-CoA reductase). Here, we report the identification of a Kazak dandelion gene TkHMGR1 that is highly expressed in root tissue, where most of the rubber is made and stored in this plant. This gene will be a valuable tool in our efforts to increase rubber production through genetic engineering in Kazak dandelion and other rubber-producing plants.
Technical Abstract: Kazak dandelion (Taraxacum kok-saghyz, Tk) is a rubber-producing plant currently being investigated as a source of natural rubber for industrial applications. Like many other isoprenoids, rubber is a downstream product of the mevalonate pathway. The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) enzyme catalyzes the conversion of 3-hydroxy-3-methylglutaryl- CoA to mevalonic acid, a key regulatory step in the MVA pathway. Such regulated steps provide targets for increases in isoprenoid and rubber contents via genetic engineering to increase rate-limiting enzyme activities. In this study, we identify a TkHMGR1 gene that is highly expressed in the roots of Kazak dandelion, the main tissue where rubber is synthesized and stored. This finding paves the way for further molecular and genetic studies of the TkHMGR1 gene, and its role in rubber biosynthesis in Tk and other rubber-producing plants.