海藻酸寡糖诱导黄瓜抗灰霉病效果及其机理研究

为了研究海藻酸寡糖对黄瓜灰霉病的防治效果及诱导抗病机理，以黄瓜感病品种3叶期植株为试材，通过盆栽试验、酶活测定法和实时荧光定量，测定接菌后0~48 h内，黄瓜叶片的防御相关酶活性\超氧化物歧化酶（SOD）活性、氧化氢酶（CAT）、苯丙氨酸解氨酶（PAL）活性、氧化物酶（POD）活性\]和信号转导途径关键基因表达量（茉莉酸途径关键基因 JAR1和 EIN2；水杨酸途径关键基因 NPR1和 PR1）。结果表明：①海藻酸寡糖的最佳诱导浓度为50 mg/L，诱导时间为3 d，防效可达66.75%；②防御相关酶的活性均显著提高；③水杨酸途径关键基因 NPR1和 PR1相对表达量均上调。可见海藻酸寡糖通过激发水杨酸信号转导，提高植株体内防御相关酶活，增加植株抗病性。

Effciency of Alginate Oligosaccharides on Induced Resistance against Botrytis cinerea in Cucumber and Their Mechanisms

In order to investigate effect of alginate oligosaccharides on induced resistance against Botrytis cinerea in cucumber and understand their mechanisms,the trefoil stage of a susceptible variety of cucumber was used as the experimental materials. During 0-48 h after inoculation in pot experiment,enzyme activity determination method and real-time fluorescence quantification were used to determine the activities of defense related enzymes \(superoxide dismutase (SOD),hydrogen oxide (CAT),phenylalanine ammonia lyase (PAL)\],and peroxidase (POD) activity in cucumber leaves. The expression of key genes in the signal transduction pathway,including JAR1 and EIN2 ( key gene of plant in Jasmonic Acid Pathway),as well as NPR1 and PR1(key gene of plant in Salicylic Acid Pathway),were analyzed. The results showed that the optimal induction concentration of ADO was 50 mg/L,with the induction period of 3 days,and the control efficiency of 66.75%; the activities of defense related enzymes significantly increased; the relative expression of NPR1 and PR1,key genes of salicylic acid pathway,were up-regulated. Thre results suggest that alginate oligosaccharides have the potential to enhance the activity of defense related enzymes in plants,thereby increasing plant disease resistance through the stimulation of salicylic acid signal transduction.