【作者】 王东辉；

【导师】 梁宗锁；

【作者基本信息】 中国科学院研究生院（教育部水土保持与生态环境研究中心） ， 生态学， 2010， 博士

【摘要】 植物次生代谢物在人类生活中有十分重要的作用,在植物体内含量多少受多个生态因子共同影响。近些年来,植物生理生态研究者逐渐认识到植物次生代谢产物广泛的生物学效应,如化感作用、生物驱虫等,研究这些化合物在植物生命活动以及生态系统中可能扮演的角色成为国内外植物生理与生态学者们的研究热点。植物在转变成药用植物的栽培过程中,经历了生态系统的转变,从原来的生态系统转变为农业生态系统。生物多样性变少,人类活动影响的增加,如果忽视药用植物在多种生物和环境作用下形成的特殊代谢途径,改变植物的生长环境,减少药用植物与原来生境的交互作用,长期种植,必定会使原来的与其生境“交流”能力降低,而药用植物次生代谢强度正和植物与生境间的“交流”作用密切相关。玄参具有凉血滋阴、泻火解毒之功效,随着中药产业化的快速发展,使用和需求量日益扩大。与其它药用植物相比,可以说玄参次生代谢的影响因素的研究才刚刚起步,探索不同生态因子对玄参次生代谢的影响对玄参的理论研究和生产应用都具有十分重要的作用。因此,借鉴其它药用植物的如红豆杉、丹参、柴胡等研究成果,对我国栽培的玄参通过调查采样、智能气候培养箱培养以及室内分析等研究手段,以植物次生代谢理论和植物生理生态学等学科的研究为基础,详细研究了不同生态因子对玄参次生代谢物含量的影响,主要取得了以下结论:(1)全国八个产地:河北安国、陕西杨凌、陕西镇坪、湖北巴东、湖南龙山、重庆南川、浙江东阳和浙江仙居的玄参中主要活性成分,如梓醇、桃叶珊瑚苷、哈巴苷、哈巴俄苷和肉桂酸,含量差异显著。年降水量和七月平均气温对玄参次生代谢物含量影响较大。降雨量通常对植物蒸腾作用和生长发育影响较大,而对光合作用影响较小。在一定范围内,降雨量减少可以为玄参提供了相对较多的碳水化合物用于次生代谢,所以玄参中次生代谢物含量增加。七月是玄参由营养生长向生殖生长转化的时期,较高的温度促使玄参消耗较多的碳水化合物用于生殖生长,进而减少次生代谢的前体物质,所以次生代谢物含量降低。(2)对于幼苗期玄参来说,从抗氧化保护酶活性变化过程来看,不同生态型表现出不同的抗旱性,来自于河北安国生态型抗旱性最强,重庆南川的生态型次之,浙江东阳的生态型最弱。水分胁迫对玄参次生代谢物含量有重要影响,轻度水分胁迫可促进哈巴苷和哈巴俄苷的合成,较重的水分胁迫可促进梓醇和桃叶珊瑚苷的积累。水分胁迫不利于肉桂酸的合成和积累。水分胁迫引起次生代谢物含量的变化可能与超氧自由基浓度变化有关。(3)对于盛花期玄参来说,由于高温胁迫破坏了叶片的光合系统,造成叶绿素荧光值下降,合成的碳水化合物减少,而玄参生殖生长也需要消耗大量的碳水化合物,所以会引起合成次生代谢物的底物减少,造成次生代谢物含量下降的结果。在五种化合物中,哈巴俄苷含量对高温胁迫最敏感。盛花期玄参能够忍耐短时间的高温胁迫,不同的来源的生态型耐高温胁迫能力不同,来自重庆南川的耐高温胁迫能力最强,浙江东阳的次之,河北安国的最弱,这与它们长期适应当地气候有关。(4)茉莉酸甲酯和水杨酸作为两种比较常见的具有生物活性的化合物,其溶液胁迫都能引起玄参叶片超氧阴离子浓度和抗氧化酶活性变化,前者能够使超氧阴离子浓度持续上升和次生代谢产物如梓醇,哈巴苷,桃叶珊瑚苷和哈巴俄苷含量上升,而水杨酸胁迫只能使超氧阴离子浓度短时间上升,而对玄参次生代谢无明显诱导作用。(5)茉莉酸甲酯作为植物信息激素的一种,外源添加可以起植物的防御性反应和促进次生代谢活动。利用茉莉酸甲酯溶液短期浸泡玄参鲜根和组织,可显著提高梓醇、哈巴苷、桃叶珊瑚苷和哈巴俄苷的含量。在人工栽培药用植物过程中,合理使用植物信息激素恢复药用植物的次生代谢潜能,必将安全的、有效的和稳定的提高植物药材的质量。(6)病源微生物的入侵,通常会引起植物的防御性反应。由经高温灭活的杨树溃疡病菌、棉花枯萎病菌、烟草赤星病菌、南瓜枯萎病菌和白菜黑斑病菌的制成诱导子对玄参无菌苗进行诱导试验,结果表明只有杨树溃疡病菌诱导子具有较强的诱导玄参次生代谢物含量增加的活性。通过进一步试验发现,由灭活的杨树溃疡病菌制成诱导子,可显著提高玄参组织中的次生代谢物,如梓醇、桃叶珊瑚苷、哈巴苷和哈巴俄苷含量。四种化合物含量在诱导处理最合适浓度有所不同,诱导处理后含量变化规律各不相同,它们在玄参体内可能存在相互转化的机制。更多还原

【Abstract】 Medicinal plant secondary metabolites have an important role in human life, and their contents in plants are affected by multiple ecological factors. In recent years, it is increasingly recognized by plant physiology and ecology researchers that plant secondary metabolites have a wide range of biological effects and may play an important role in the plant life and ecosystems.In cultivation process, medicinal plants are transferred from the original ecosystems into agro-ecosystems and programmed loss of biodiversity, and increased human impact. Neglecting that wild medical herbs have formatted a special metabolic pathway in a variety of biological and environmental effect, changing herbs growing environment, reducing the interaction of herbs and their habitats, long-term cultivation will make "intercommunion" capacity of the medical herbs reduce. However, secondary metabolites strength of medical herb is closely related with the "intercommunion" capacity of the plants.Radix Scrophulariaceae has an important use in cooling blood, detoxification and antimycobacterial. With the rapid development of Chinese medicine industry, Radix Scrophulariaceae is used and demanded more and more. Compared with other medicinal plants, it can be said that the research on ecological factors on the secondary metabolism of Scrophulariaceae just started. So, to explore different ecological factors on secondary metabolism of Scrophularia ningpoensis Hemsl is very important in theoretical and production. Therefore, we can only learn from other medicinal plants such as Taxus chinesis var mairei, Salvia miltiorrhiza, Bupleurum chinense and other researches. By the field investigation, and the intelligent climate incubator development, and the analysis of indoor means to plant secondary metabolism of plant physiological ecology theory and research-based disciplines to study the different ecological factors on the content of secondary metabolites in S. ningpoensis, we mainly made the following conclusions:1. From the eight regions S. ningpoensis producted in China, such as Anguo in Hebei Province, Yangling and Zhenping in Shaanxi Province, Bangdong in Hubei Province, Nanchuan in Chongqing City, Longshan in Hunan Province, Xianju and Dongyang in Zhejiang Province, the contents of the main active ingredient of Radix Scrophulariaceae, such as catalpol, aucubin, harpagide, harpagoside and cinnamic acid, were disparities. Annual precipitation and July temperature had more effect on the content of secondary metabolites of Radix Scrophulariaeciae than any other climatic factors. The effect of rainfall on plant transpiration and growth and development is more obvious than that on the photosynthesis. Within a certain range, reduced rainfall could provide a relatively more carbohydrates to S. ningpoensis plants for the secondary metabolism, so S. ningpoensis increased the levels of secondary metabolites. July is the time that S. ningpoensis transformates from vegetative growth to reproductive growth, higher temperatures promote greater consumption of carbohydrates of S. ningpoensis for reproductive growth, thereby reducing the content of secondary metabolites2. To S. ningpoensis seedlings, the drought resistances of different sources of S. ningpoensis ecotypes were quite different. The drought resistance of ecotype from Anguo, Hebei Province was the strongest, and that from Nanchuan in Chongqing City was the second, and that from Dongyang in Zhejiang Province was the worst. The mild water stress was conducive to harpagide and harpagoside accumulation, severe water stress was conducive to aucubin and catalpol accumulation, but water stress was not conducive to the accumulation of cinnamic acid. The changes in levels of secondary metabolites by water stress induced may be related to the changes in the concentration of superoxide radical.3. To flowering S. ningpoensis plants, high temperature stress damaged their photosynthetic system, and resulted their chlorophyll fluorescence decreased, so the synthesis of carbohydrates decreased. While the S. ningpoensis reproductive growth also consumed a lot of carbohydrates, it will lead to synthesis of secondary metabolites reduced on the substrate material, resulting secondary metabolites decreased. In the five compounds, harpagoside content was the most sensitive to high temperature stress. Flowering S. ningpoensis could tolerate a short period of heat stress. And the high temperature stress resistances of different sources of S. ningpoensis ecotypes were quite different. The high temperature stress resistances of the ecotype from Nanchuan in Chongqing City was the strongest, and followed by that from Dongyang in Zhejiang Province, and that from Anguo in Hebei Province was the weakest. This may relate with their long-term adaptation to local climate.4. Methyl jasmonate and salicylic acid stress both could cause superoxide anion and antioxidant enzyme activity in the leaves of S. ningpoensis changed, the former would keep on rising to superoxide anion concentration and increasing secondary metabolites such as catalpol, harpagide, aucubin and harpagoside content, while salicylic acid stress could only make short-term increase in superoxide anion concentration and no significant effect on the secondary metabolism. 5. As a plant information hormone, methyl jasmonate as an external source could induce the defensive reaction of the plant and promot of secondary metabolite content. If the fresh root and organizations of S. ningpoensis were short-term soaked in methyl jasmonate solution, the catalpol, harpagide, aucubin and harpagoside contents in them could be significantly improved. In the process of the artificial cultivation of medicinal plants, the felicitous use of plant information hormones could recovery the potential of secondary metabolites in medical plants. This will bound to be a safe, effective, stabilite way to improve quality of medicinal plants.6. The invasion by pathogenic microorganisms, usually cause plant defense response. The five different sources fungal elicitors were tested in the induction of S. ningpoensis sterile test. We found that only Dothiorella gregaria elicitor can induce secondary metabolites in S. ningpoensis increased. The further experiments showed that the Dothiorella gregaria elicitor could significantly increase secondary metabolite contents in the S. ningpoensis organization, such as catalpol aucubin, harpagide and harpagoside. The content of the four compounds induced by Dothiorella gregaria elicitor changed in different way in the experiment. They may change into each other in S. ningpoensis.更多还原