| Scutellaria baicalensis Georgi(S. baicalensis) is an herbaceous perennial plant used as a medicinal plant, which roots have been used for cleaning away heat, moistening aridity, purging fire, detoxifying toxicosis, and is also anti-abortion agent. With the in-depth study on medicinal functions, the market demand of S. baicalensis greatly rises. But the wild resource was explosively exploited in the long time and is dying out in most regions. The manual planting is also confronted with many problems such as the long life cycle, the low livability, the excessive residual pesticide and the main activity constituents with low content. At present, plant cell culture is one of the most important ways to produce secondary metabolite many Chinese traditional and herbal drugs.In this dissertation, following the basic principles of biology, and the help of the multi-subject analysis, the author studied the regulation, biosynthesis and accumulation rules of baicalin in S. baicalensis callus. Its objective is not only to discuss the possibility of industrialization for S. baicalensis but also to provide the theory base for the field planting. Furthermore, the important conclusion will be applied to improve the yield of S. baicalensis by the farm planting and the farm mode will be optimized by our experiment.In this dissertation paper, callus was induced by plant cell culture technology. The content of baicalin was determined by HPLC. Different carbon source, nitrogen source, growth regulating substance, KH2PO4 and organic addition were added to media. Their effects on baicalin and flavonoid content of S. baicalensis callus were studied. Three precursors (sodium acetate, L-phenylalanine and tyrosine) and three elicitors (ammonium ceric nitrate, silver nitrate and salicylic acid) were also added to the media. Their effects on callus growth and the baicalin accumulation of S. baicalensis callus were studied.The results show as follows:The growth of S. baicalensis callus and the synthesis of baicalin were notin-phase;Callus grew firstly and then synthesized its secondary metabolism products. It is obvious for sucrose to regulate the synthesis of baicalin. When the concentration of sucrose was <3%> it can only promote the callus growth;When 3%~8%, it can greatly increase not only the callus growth but also the synthesis of baicalin;When 8%, both them arrived at the maximum content;When arrived at 10%, Both them began to be inhibited slightly.In the dark culture, the optimal medium for the callus growth and the synthesis of total flavonoids and baicalin of S. baicalensis is: MS medium, 60 mmolL'(NH4+: NO3"=1 : 1), 1.5 mmol-L"1 KH2PO4, 80 g-L"1 sucrose, 0.3 mg-L"1 IAA, 2 mg-L'16-BA and 200 mg-L"1 peptone. At (25 ± 1)°C, after culture for 40 d, the total biomass reached 28.7 g-L"1 and the total flavonoids achieved 354.6 mg-g"1. The baicalin content and yield that were 167.4 mg-g"1 and 4.8 g-L'1 were 5.54 times and 18.2 times of the control, respectively.Of the three investigated precursor, sodium acetate was found to be the best, and at the concentration of 0.5 mmol-L"1, the baicalin yield was enhanced 76% compared with the control. Both silver nitrate and salicylic acid inhibited the synthesis of baicalin, but ammonium eerie nitrate (0.01 mmol-L"1) had significant promoting effect on the yield of baicalin that was increased 112%.The yield of baicalin was finally raised 161% and achieved 1.33 g-L"1 by the co-regulating of sodium acetate (0.5 mmol-L"1) and ammonium eerie nitrate(0.01 mmol-L"1). Adding precursors and applying elictors in the media were both effective approaches to enhance baicalin yield in S.baicalensis callus.
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