牛蒡低聚果糖诱导植物系统抗性的研究

【作者】 王进昌；

【导师】 陈靠山；

【作者基本信息】 山东大学 ， 生物化学与分子生物学， 2006， 硕士

【摘要】 牛蒡低聚果糖(Burdock Fructooligosaccharide)是本课题组从耐盐植物牛蒡(Arctium lappa L．)根中提取的一种果糖低聚糖，由12个呋喃型果糖与一个吡喃型葡萄糖组成。本论文以黄瓜为模式植物，对牛蒡低聚果糖诱导植物抗病性进行了系统的研究，从与抗性相关酶活性与内源信号分子的角度阐述了诱导抗性的作用机理，以期为牛蒡低聚果糖作为抗病诱导子的应用提供科学依据。研究结果总结如下。 1 牛蒡低聚果糖对黄瓜炭疽病的诱抗效果：黄瓜幼苗用5.0mg／mL的牛蒡低聚果糖预先诱导后再接种炭疽病菌，以病斑数计算的抗病效果达到了50.01％，而以病斑面积计算的抗病效果达到了56.83％。这表明牛蒡低聚果糖能有效地诱导黄瓜对炭疽病的抗性。 2 不同浓度牛蒡低聚果糖对黄瓜幼苗防御酶和β-1，3-葡聚糖酶活性的影响：使用梯度浓度牛蒡低聚果糖(0、1.0、3.0、5.0、7.0、9.0mg／mL)处理黄瓜幼苗4天后，不同的酶的活性变化不同。与抗性呈正相关性的PPO、SOD、POD、β-1，3-葡聚糖酶的活性在诱导后活性上升，与抗性呈负相关性的CAT酶在诱导后活性下降。在设计浓度范围内，不同酶的活性达到最大诱导程度所需牛蒡低聚果糖的浓度不同。PPO酶在7.0mg／mL牛蒡低聚果糖诱导时活性最高，SOD酶在5.0mg／mL牛蒡低聚果糖诱导时活性最高，POD酶在3.0mg／mL牛蒡低聚果糖诱导时活性最高，β-1，3-葡聚糖酶在5.0mg／mL牛蒡低聚果糖诱导时活性最高，CAT酶活性在5.0mg／mL牛蒡低聚果糖诱导时活性达最低。从不同浓度牛蒡低聚果糖对防御酶和β-1，3-葡聚糖酶活性的影响来看，牛蒡低聚果糖诱导黄瓜抗性的最适浓度是3.0～7.0mg／mL。 3 5.0mg／mL牛蒡低聚果糖诱导后防御酶、β-1，3-葡聚糖酶活性与木质素含量在不同时间的变化：用5.0mg／mL的牛蒡低聚果糖诱导后，PPO酶的活性从第4天开始持续升高，第6天时比同期对照高279.6％；SOD酶的活性在诱导后第1天就开始上升，在第3天到达峰值，比同期对照高117.3％；CAT酶的活性在诱导后第1天稍有上升，但在第2、3天开始降低，分别比同期对照降低23.50％和29.36％，第2天为最低值，在第4、5、6天活性上升，都高于同期对照；POD酶的活性在诱导后即开始持续上升，在第4天到达峰值，比对照高出184.3％；β-1，3-葡聚糖酶更多还原

【Abstract】 Burdock Fructooligosaccharide is a kind of oligofructose extracted from the roots of salt-tolerant Burdock (Arctium lappa L.) by our group, which consisted of 12 fructofuranose and 1 glucopyranose. In this paper, resistance to plant diseases was systematically studied, which induced by Burdock Fructooligosaccharide in cucumber. And the mechanism of induced resistance was demonstrated through changes of enzymes activity and endogenous signal molecules content. Followsing conclusions can be made from the study.1 Resistance effects of cucumber to anthracnose were studied after employing 5.0mg/mL Burdock Fructooligosaccharide on cucumber seedlings. The results show that cucumber seedlings had significant resistance to anthracnose after induced by 5.0mg/mL Burdock Fructooligosaccharide. Compared with the controls, the number of lesions decreased 50.01% in cucumber leaves previously treated with Burdock Fructooligosaccharide after inoculated Colletotrichum lagenarium, at the same time the area of lesions decreased 56.83% in cucumber leaves.2 Effects of different concentration Burdock Fructooligosaccharide were studied on activities of defense enzymes and β -1,3-glucanase in cucumber leaves. The results show that the activities of those enzymes positively correlated with disease resistance increased after induced by Burdock Fructooligosaccharide, such as PPO, SOD, POD, β -1,3-glucanase, and the activity of CAT negatively correlated with disease resistance decreased after induced by Burdock Fructooligosaccharide. Different enzymes reached maximum or minimum activities at different concentrations of Burdock Fructooligosaccharide. PPO, SOD, POD, β -1,3-glucanase reached maximum activities at concentrations of 7.0, 5.0, 3.0, 5.0mg/mL Burdock Fructooligosaccharide respectively, and CAT reached minimum activity at concentration of 5.0mg/mL Burdock Fructooligosaccharide. Therefore, the optimum concentration of Burdock Fructooligosaccharide which induce disease resistance of plants is 3.0~7.0mg/mL.3 Effects of 5.0mg/mL Burdock Fructooligosaccharide on activities of defense.更多还原