基于活性氧的黄芩药材道地性质量形成机制的研究

Environment can change secondary metabolism of Scutellaria baicalensis. How do the arid environment (physical factors) work with plant metabolism(chemical reactions)? This procedure must be done through some certain micro-matters. According to the relationg between seguence of physiological changes and effects of intermediate products, the active oxygen species(ROS) can completely possess such specific action among numerous substances. The study aim at (1) with metabonomics method and DD-PCR, clarifying the effect of ROS（O2- and H2O2） and of the drought on secondary metabolism of S. baicalensis at the level of cell, leaf, and root, expliciting secondary metabolism pathways according to specific markers from ROS or the drought; (2) depending on relationship between ROS, antioxidant system, and genetic expression, confirming that ROS is the essential of changed secondary metabolism; (3) evaluating medical material quality dealt with ROS according to main active composition, and finger printing. Based on ecologicalfactors-ROS-secondarymetabolism associations, as well as similarity of secondary metabolism pathways resulted from ROS and the drought, it is expected to be clarified the machinism of high-quailty drug formation, and to establish research methods of improving drug quailty, and then to provide a new platform for medicine plant cultivation production initially.

环境可改变黄芩的次生代谢。干旱等环境（物理因子）与植物体内代谢（化学变化）如何沟通？其途径需要某些微观物质来实现。根据植物生理变化发生顺序及各中间产物的生理效应，在众多物质中活性氧具有这种独特效应。本课题研究内容：（1）采用代谢组学及差异显示技术从细胞、器官（叶和根）层次研究活性氧（O2-和H2O2）和干旱对黄芩次生代谢的影响，寻找活性氧和干旱条件下的特异标记物，明确代谢途径变化轮廓；（2）根据活性氧、植物信号分子、抗氧化酶活性和次生代谢产物合成关键酶的基因表达特征等因素之间的关系，证实活性氧是次生代谢途径改变的本质；（3）从主要活性成分含量、指纹图谱等方面确认活性氧干预下的药材质量。通过以上研究确定“生态因子-活性氧-次生代谢”三者之间关系及活性氧与干旱对代谢途径改变的相似性，阐明药材优质特性形成的机理，建立道地药材质量形成研究方法，为优质中药材的栽培生产提供新的平台。

近百年来，人口急剧增加，资源破坏严重，栽培药材成为商品的主要来源，质量与环境密切相关，栽培条件下也导致了药材质量的下降，于是有了“传统中药不复存在，中医要完了”、“中医将亡于中药”的说法。提高栽培中药材质量是中药资源学研究的重点和难点，急于寻找一种有效的方法。黄芩药材具有明显的道地性，干旱和强光照等逆境是促进黄芩质量形成的主要因素。干旱等环境（物理因子）对植物体内代谢（化学变化）可能是通过活性氧来实现的。基于此假说，采用代谢组学研究显示活性氧（O2-和H2O2）与干旱作用相似，减弱了黄芩初生代谢，增强了次生代谢，黄酮含量增加，特别是显著增加多羟基和多甲氧基黄酮苷元类等活性较强成分含量。黄芩植株地上部分和鲜根喷施不同浓度的H2O2和Na2S2O4后，黄芩地上部分相关抗氧化酶活性均有不同程度的改变，苯丙氨酸解胺酶（PAL）活性的升高。采用H2O2和Na2S2O4处理地上部分，0.004μmol/LH2O2组的黄芩苷和汉黄芩苷含量分别比对照组降低了5.9%和7.2%，但活性较高的黄芩素和汉黄芩素含量分别比对照提高了2.46倍和0.83倍。0.004μmol/L Na2S2O4组的黄芩苷和汉黄芩苷含量分别比对照降低了2.2%和2.1%，黄芩素和汉黄芩素含量分别比对照提高了2.27倍和1.96倍。黄芩鲜根喷施不同浓度的H2O2和Na2S2O4后，20μmol/L H2O2处理组黄芩素的含量从0.19%升高到0.57%，汉黄芩素的含量从0.11%升高到0.30%。40μmol/L Na2S2O4处理组黄芩素的含量从0.28 %升高到1.96 %，汉黄芩素的含量从0.14%升高到1.24%，分别达到7倍以上。活性氧能够引发干旱条件下的次生代谢，阐明植物适应环境的生物学机制和药材优质特性形成的机理，建立道地药材质量形成研究方法和优质药材生产技术。