The Effect Of Anti-sense Squlene Synthase Expression On Artemisinin Biosynthesis

Artemisinin is a new effective antimalarial drug extracted from the medicinal plant Artemisia annua L., but the content of artemisinin is low in the Artemisia annua. With the successful cloning of genes involved in the biosynthesis of artemisinin, genetic engineering is thought to be one of the most promising approaches to enhance the production of artemisinin. During the transformation of Artemisia annua, an effective and steady shoot-inducing system is important for successful plant transgormation. However, during the subculture of Artemisia annua, the ability of shoot regeneration become lower and lower. In this paper, the effects of filter paper on the shoot induction and genetic transformation of Artemisia annua were studied.Followed these results, the effect of anti-sense mediated inhibition of squalene synthase expression on artemisinin biosynthesis was studied, the main results are: The effects of filter paper on the shoot induction and genetic transformation of Artemisia annua were studied. The results revealed that laying a piece of filter paper on the shoot-inducing medium could markedly enhance the formation of shoot, and the frequency of shoot induction could reach as high as 97%. Based on this highly efficient shoot induction system, we further investigate the effect of filter paper on the genetic transformation of Artemisia annua by Agrobacterium tumefaciens. With the optimized transformation system, Kan-resistant shoot induction frequency could reach 59.7%,of which 12.5% could root on the root-inducing medium and all the rooted plants were PCR- positive. Stable GUS expressions were observed in some of the PCR-positive plants.Using the above improved genetic transformation system, we have got some transformed plants of anti-sense squalene synthase gene. PCR analysis and Southern blotting result indicated that the anti-sense squalene synthase gene has been successfully introduced into the genome of Artemisia annua. RT-PCR result revealed that the squalene synthase gene has been partly inhibited on the mRNA level in the...