Ri质粒转化的青蒿发根培养及青蒿素的生物合成

用发根农杆菌(Agrobacterium rhizogenes)转化药用植物青蒿(Artemisia annua L．)并建立了发根体外培养系统。Southern杂交、NPT Ⅱ酶的检测证明Ri质粒的T—DNA转移并整合到植物的核基因组上。在发根培养系统中，检测了青蒿的重要次生代谢物一青蒿素的含量，检测了不同理化因子对发根生长及青蒿素含量的影响。结果表明：光照(日光灯，12h光周期，20001x)有利于次生产物青蒿素的积累。培养基的pH值为5．4。蔗糖浓度为3％不仅促进发根的生长，而且促进青蒿素的积累。低浓度萘乙酸(NAA)对发根生长具有促进作用，但抑制青蒿素的合成。赤霉素GA，对发根的生长及次生产物的合成都具有促进作用，其最适浓度为4．8mg／L。

Hairy Root Culture of Artemisia annua L. by Ri Plasmid Transformation and Biosynthesis of Artemisinin

Hairy root culture system of medical plant Artemisia annua L. was established by infection with Agrobacterium rhizogenes R 1601. The transgenic state of transformed roots was confirmed by Southern blot hybridization with TL-DNA o'f pFw302. The expression of NPT I gene was comfirmed by enzymic assay. The important secondary metabolites-artemisinin was obtained in the hairy root cultures. The effects of various physical and chemical factors on the growth of the hairy roots and production of artemisinin were studied. Artemisinin could be detected in hairy root cultures in the light. The optimum pH value of medium was 5. 4. Fast growth of the hairy roots and maximal production of artemisinin was observed in the presence of 3% sucrose. Low concentration of NAA (0. 025mg/L) enhanced the growth of the roots, but inhibited the production of artemisinin. The growth and artemisinin production in hairy root cultures were greatly promoted by addition of GA3 to the medium. Its optimum concentration was 4. 8mg/L.