Effect Of Cadmium On The Growth And Cadmium Absorption Of The Replant And Hair Roots Of Datura Metel L.

Datura metel L., which is also named flos daturae, trempet flower and brachybotrys paridiformis, is belonging to Solanaceae, Datura. It is a natural herbaceous plant, and has an important use in pharmacy. The major contents of Datura metel L. are atropine, hyoscyamine and scopolamine. On that account, the aim of our experiment is to build and optimize the tissue culture and rapid propagation system of Datura metel L., and to provide a reference for enlarging cultivation and building the genetic transformation system of Datura metel L. Meanwhile, the establishment of hair root induction and culture system in Datura metel L. can lay the foundation of industrial scale production about the hyoscyamine and scopolamine. And we explore the possibility on using hairy roots with rapid automous growth as a sensitive environment evaluation system of heavy metal pollution.1.To study the condition of plant regeneration and clonal propogation system of Datura metel L. Stems and leaves of Datura metel L. were used as explants, effects of different hormones for callus induction and plant regeneration of leaves and clonal propogation system of stems were studied and optimized. The optimal medium for callus of leaves was MS+1mg-L-16-BA+0.1mg·L-1NAA; The optimal medium for callus induction of clustered buds was MS+2mg-L-16-BA+0.2mg-L-1NAA; The optimal medium for clonal propogation system of stems was MS+3mg-L-16-BA+0.05mg-L-1NAA. The best medium and plant growth substances combination for rooting induction was MS+0.5mg-L-1BA. Transplant survival rate of plantlet reached more than90%in humus soil-pearlite(5:1). We establish the condition of plant regeneration and clonal propogation system of Datura metel L.2.To establish the hair roots culture system of Datura metel L and study the hairy roots growth and biosynthesis of scopolamine and hyoscyamine in hair roots culturing system. Direct degermed cotyledon of wild Datura metel L was infected by Agrobacterium tumefaciens strain C58C1to obtain hair roots. Growth curves and scopolamine and hyoscyamine biosynthesis curveswere determined. The scopolamine and hyoscyamine from different hair roots lines were examined by HPLC. Hairy roots induction rate reached70%. After25days cultured in1/2MS liquid nutrient medium, the hair roots weight, content of scopolamine and hyoscyamine reached maximum, tow high efficient accumulation hyoscyamine and scopolamine hair roots lines were obtained. The medial accumulation coefficient of hyoscyamine and scopolamine were2.53times and5.37times compared with the leaves of wild Datura metel L respectively. The established hair roots induction and culture system of Datura metel L provided a foundation for further obtaining scopolamine and hyoscyamine.3.To study if the replant and hairy roots of Datura metel L can be used for phytoremediation of Cd contamination, we investigated the effects of cadmium(Cd), content of soluble protein and activities of superoxide (POD and SOD), MDA, Cd2+absorption in replant and hair roots of Datura metel L. The main results were as follow: Cd concentration of the50μmol·L-1enhanced the growth of replant and hairy roots, made be branched roots long and strong; while100μmol·L-1inhibit the growth of the replant, but the hairy roots growthed nomal hardly. Insiste with the control, the soluble protein content was hingest in the replant when it was cultured in the50μmol·L-1Cd2+for9days, but the highest of the soluble protein content of the hairy roots was in the100μmol·L-1Cd2+for9days. When we cultured the plants with Cd2+in different concentration, the SOD activity of regenerated plants of Datura metel L and their hairy root showed increasing while the Cd+concentration increased. It is worth mentioning that, after dealing with the300μmol·L-1Cd2+,the plants showed the better SOD activity compared with the control. Meanwhile, the SOD activity of hairy root had a growth tendency when we conducted them with50μmol·L-1Cd2+. The difference between the regenerated plants and their hairy root was the change trend of their POD activity. The POD activity of regenerated plants had the rising trend with the Cd2+concentration, and hairy root had the strongest activities when the Cd2+concentration was100μmol·L-1. Comparing with the control, the contents of MDA in regenerated plants and their hairy root were increased after dealing with Cd2+, and the contents had a growth tendency with the adding of Cd2+concentration. With the Cd2+concentration enrichment, the absorbing and adsorption capacity of regenerated plants and their hairy root presented the first after rising downward trend. The difference was, the absorbing and adsorption capacity of regenerated plants and their hairy root showed decreased when the Cd2+concentration was300μmol·L-1.The results showed that D. metel hairy roots has a strong Cd tolerance. This has laid a preliminary experimental and technological foundation for using D. metel hairy roots-regenerated plants with well-developed root system to do phytoremediation of Cd contamination and also provided the possibility on using hairy roots with rapid automous growth as a sensitive environment evaluation system of heavy metal pollution.