인삼에서 Farnesyl Diphosphate Synthase 과발현이 진세노사이드 생합성에 미치는 영향

Abstract

FPS (farnesyl diphosphate synthase) plays an essential role in organ development in plants. However FPS has not previously been identified as a key regulatory enzyme in triterpene biosynthesis. In order to investigate the effect of FPS on ginsenosides biosynthesis we over expressed FPS of Centella asiatica (CaFPS) in Panax giseng adventitious roots. PCR analysis showed the integrations of the CaFPS and hygromycin phosphotransferase genes and we ultimately selected three lines. The result of Southern blot analysis demonstrated the introduction of the CaFPS gene into genome of ginseng. In addition the results of RT-PCR analysis revealed that CaFPS gene overexpression induced an accumulation of its transcrip-tion in the ginseng adventitious roots. To determine whether or not the overexpression of the CaFPS gene contributes to the downstream gene expression associated with triterpene biosynthesis the level of mRNAs was analyzed by real-time PCR. The result showed that no differences were detected in any expression of all genes. To determine quantitatively the content of ginsenosides in transgenic ginseng adventitious roots HPLC analysis was conducted. The content of total 7 ginsenosides was increased to 1.8 1.4 and 1.7 times than that of the controls respectively. This indicated that the overexpression of CaFPS in ginseng adventitious roots causes an increase in ginsenoside content although down stream genes of FPS gene were sup-pressed by CaFPS overexpression.