【作者】 王晶波；

【导师】 王伯初；

【作者基本信息】 重庆大学 ， 药物化学， 2005， 硕士

【摘要】 本实验采用两种类型的诱导子外源处理黄瓜幼苗叶片,探讨了诱导子对提高黄瓜对黑星病菌抗病性的作用,并探讨了外源诱导子对植物次生代谢物的诱导生成的效果和机理。结果表明:诱导子外源处理植物生体能够诱导新的活性物质产生或诱导原有活性成分增加。这一研究成果对相关植物次生产物（如农药活性物质和医药活性物质）的代谢机理及其应用研究具有重要的参考价值。1.诱导子诱导黄瓜幼苗的抗病性:以二真叶龄的黄瓜幼苗为实验材料,首先筛选出最佳诱导作用的力学参数,然后采用水杨酸和压应力外源处理,接种后考查抗性表达,发现水杨酸和压应力都可以诱导提高黄瓜幼苗对黑星病菌的抗性。对黄瓜幼苗的第二片真叶的成份进行分析,并与对照（未经诱导的黄瓜幼苗的第二真叶）相比较发现,经诱导后,黄瓜幼苗的第二真叶中木质素含量增加,且生成多种植保素。因此,用诱导子处理黄瓜幼苗的第一片真叶后,在第二片真叶中可以产生木质素沉积现象,且两种诱导子都可以诱导产生植保素。研究结果可以作为黄瓜黑星病害生物防治的理论依据。压应力的诱导活性也进一步得到验证,为其在生物防治上的应用提供了理论依据。2. 诱导子在黄瓜幼苗中抗病信号的转导:在诱导之前,处理组植株用一定浓度的RGD（Arg-gly-Asp）序列的多肽和与前者序列相反的DGR 多肽处理,空白对照组用对应量的水处理。再将每处理组分为接受挑战接种和非挑战接种两部分,之后考查处理组的发病情况,并考查各组的木质素沉积和植保素积累和H₂O₂含量情况。发现经RGD 处理再诱导后各指标情况均与空白的非诱导组相似,而经DGR处理再经诱导后所产生的诱导效果与经压应力和水杨酸直接刺激的诱导效果极其相似。因此,压应力和水杨酸两种诱导子对黄瓜抗黑星病的诱导作用依赖于植物细胞膜和细胞壁之间的RGD 特异介导的粘附,信号传导途径推测和哺乳动物中类似,即“ECM-整合素-细胞骨架”的信号传导系统。3.本实验还分析了诱导子的作用效果及影响因素,并阐述了诱导子作用的机理及应用前景。诱导子的作用效果与诱导子的种类、诱导处理时间长短等多种因素密切相关。诱导子引起植物代谢过程的一系列变化,最终使植物产生防卫反应,是一个连续的、信号逐级传导的过程,其作用机理十分复杂,其理论研究和应用研究均对生物学和医学具有重要意义。更多还原

【Abstract】 In this thesis, kinds of inducers were applied to cucumber seedlings, the effect and mechanism of the induction of plant secondary metabolites by inducers were explored. The result was that inducer could induce new active compositions in the plant. This result was a reference data for studies on metabolic mechanism and utility of plant secondary metabolites. 1. As to cucumber seedlings, stress and SA (Salicylic Acid) were applied to induce its disease resistance. We chose two-leaf-old cucumber seedlings as our experiment material. At first, a certain strengthen local stress and a certain content SA were stimulated on the first real leaves of the cucumber seedlings. After challenging inoculation, resistances were checked. The results were that stress and SA could both induce the resistance of cucumber seedlings to Cladosporium cucumerinum. Analysizing the chemical composition of the cucumber second real leaves, many phytoalexins and lignine were both found induced in leaves. Therefore, the result was the production and accumulation of lignine and the production and accumulation of phytoalexins after being treated of the first real leaves by inducers. The result can be regarded as a theoretical foundation. The action of the mechanical stress was verified furtherly. 2. Resistance signals transduction of inducers in cucumber seedlings. Mechanical stress inducer and chemical SA inducer were used to treat the first real leaves of cucumber seedlings. Before induced, the leaves were treated by RGD(Arg-gly-Asp) and DGR, while the controls were not treated by RGD and DGR. Each treated group was divided into two teams. One was challenging inoculated and another one not. After that, the incidence of disease of each treated group was checked. By assay the changes of the lignine and the phytoalexins, we get a result that after treated by RGD, both indexes are similar to the control while the groups treated by DGR opposite. Therefore, The stress and SA induced resistance is depended on the RGD specific mediated adhesion between cell wall and plasma membrane. There is a similar analysis between mammal cell and the plant cell on the stress signal transduction, which the signaling across a dynamic continuum involving the “ECM-Integrin-cytoskeleton”system. 3. This thesis also analysized the effect and influent factors and clarifyied the inducing mechanism and utility prospect of inducer. The effect of inducers was related to many factors such as the type of inducer, the consistency of inducer, time of the system treated by inducer. The changes of plant metabolism induced by inducer induced defensive actions in plant. It is a successive signal transduction processs. The mechanism is very difficult, but theoretical and practiceal studies on it are both important to biology and medical science.更多还原