| Scutellaria baicalensis Georgi is the dried root of the labiatae medical plant---S.baicalensis. It is bitter in taste and cold-natured, and has the effects of clearing heat and drying damp, tonifying the blood to prevent miscarriage, detoxifying, etc. Baicalin, baicalein and other flavonoid compounds are main effective ingredients of S.baicalensis.The research of the subject primarily reveals the regulative function on the accumulation of main flavonoid substances in S.baicalensis and the influence on the quality of the medicine by high temperature, low temperature and insufficient soil moisture from the view of anti-oxidant metabolism, and also primarily reveals the basic rule of the regulation of the extraneous plant growth regulator on the accumulation of baicalin, baicalein through influencing the entogenous hormone. Research results are as follows:(1)Cloning two genetic fragments relevant to plant stress resistance from S.baicalensis leaves, which are RNA-helicase and Clp prolease, and proving the high similarity of the RNA unwindase and the Clp prolease,with homologous genes of other species through homologous control. S.baicalensis is a draught-resistant traditional Chinese medicine, which establishes the base of the molecular biology for observing the draught-resistant mechanism of S.baicalensis from the regulating factor of gene transcriptional level.(2)High temperature (40℃) and low temperature (8℃) influence the accumulation of flavonoid ingredients in S.baicalensis through different ways, and form different mechanisms of action. High temperature obviously reduces the content of baicalein, and the main reason is CAT and APX anti-oxidant metabolism enzymes in S.baicalensis are inhibited, and effective ingredients of S.baicalensis participates the ROS removal of S.baicalensis under a continuous high-temperature environment. Under the low temperature condition, because the expression of CHS enzyme gene is obviously inhibited, baicalin, baicalein and total flavones contents are obviously reduced, and the anti-oxidant enzyme system and large amount of free proline play the important function of resisting oxidant stress.(3) Proper insufficient water moisture is helpful for the long-time stable accumulation of flavones ingredients in the root of S.baicalensis because draught agitation always exists but not serious to keep the accumulation of baicalein at a high level to resist the stress caused by insufficient moisture. The proline concentration, and the genetic expression amount of RNA-helicase and the Clp prolease are also obviously higher than those of the control, and it shows the adaptive regulation of S.baicalensis on the treatment.(4)Extraneous hormone influences the accumulation of secondary metabolites by entogenous hormone. The research of the experiment finds the combination of extraneous plant growth regulators which respectively and obviously improve the accumulation of baicalin and baicalein i.e, the combination of 5 mg/L NPA+1 mg/L GA3 increases 6 times of the content of scutelloside, and 5mg/L NPA+PP333 of low, middle or high concentration increases the content of scutellarin for more than 15 times. Experiments show that increasing the content of entogenous IAA is helpful for baicalin accumulation, and increasing entogenous ABA content is helpful for baicalein accumulation.The research results give a theoretical meaning for narrating the physical and ecological functions of flavonoid ingredients and the quality formation of genuine S.baicalensis medicine, provides theoretical basis for directing the production of high-quality S.baicalensis, is helpful for the sustainable development of S.baicalensis crop production, provides technical support for further enlarging and sieving better combination of plant growth regulatiors and baicalin and baicalein industrialized culturing production, and provides theoretical and technical bases for producing high-quality medicines through plant growth regulators.
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