Abstract
Ubiquinone (UQ) is a component of the mitochondrial respiratory chain, and is composed of a quinone moiety and an isoprenoid side chain. The length of side chain varies depending on the organism it derives, and is defined by the nature of the polyprenyl diphosphate synthase. In this study, decaprenyl diphosphate synthase gene (ddsA) from Gluconobacter suboxydans was introduced into rice in order to change its UQ side chain length from nine to ten. In plants, UQ biosynthesis thought to be occurred in mitochondria or ER-golgi system. Therefore, we produced three kinds of transgenic rice plants expressing DdsA targeted into mitochondria (S14-DdsA), golgi apparatus (CTS-DdsA) or cytoplasm (35S-DdsA). By western analysis, we obtained S14-DdsA and CTS-DdsA plants accumulating DdsA, but could not obtain such a 35S-DdsA plant. HPLC analysis of revealed that UQ content of CTS-DdsA plants were indistinguishable from wild type, while S14-DdsA plants produced UQ-10 (UQ content: 10 μg/gFW).
