Overexpression of 1-Deoxy-D-xylulose-5-phosphate reductoisomerase gene in chloroplast contributes to increment of isoprenoid production.

Plants synthesize a large number of isoprenoid compounds that are of industrial, nutritional and medicinal importance. 1-Deoxy-D-xylulose reductoisomerase (DXR) catalyzes the first committed step of plastidial isoprenoid-precursor biosynthesis. In the present study, we generated transplastomic tobacco plants that overproduced DXR from Synechosystis sp. strain PCC6803. The transformants showed increase in the content of various isoprenoids such as chlorophyll a, beta-carotene, lutein, antheraxanthin, solanesol and beta-sitosterol, indicating that the DXR reaction is one of the key steps controlling isoprenoid level in tobacco leaves. A qualitative change in isoprenoid composition was also observed. The growth phenotype of the transplastomic plants was similar to that of wild-type plants. These results showed that plastid metabolic engineering is useful in manipulating the yield of isoprenoids in plants.