玉米不同防卫酶系对纹枯病作用的研究

通过对玉米高耐纹枯病材料R15和高感纹枯病材料478接种高致病性的优势融合菌群AGl-IA后，设置不同时间段进行取材，测定两个材料相同部位的叶片及叶鞘的过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物酶(SOD)、苯丙氨酸解氨酶(PAL)和抗坏血酸过氧化物酶(APX)活性的变化。结果表明：高耐材料R15的叶鞘中除PAL变动不大外，POD、CAT、SOD和APX活性都有不同程度的增加，其中POD活性变化最为剧烈，叶片中POD、CAT和APX表现上升，SOD、PAL表现下降。高感材料478的POD、CAT在叶片与叶鞘中均表现上升，SOD在叶片中上升、叶鞘中下降，PAL和APX均无明显变化。表明POD、CAT水平与材料抗性呈正相关，并且上述防御酶系在植物体中的不同作用区域和作用时间相互协作，共同完成植物的抗病防御反应。

Analysis Function of Different Defense Enzymes on Maize

The activities of peroxidase(POD), phenylalanine ammonia lyases(PAL), Ascorbate Peroxidase, superoxide dismutase(SOD) and catalase(CAT) were measured in R15 and 478 both in sheathes and leaves inoculated with AG1-IA or not inoculated. The results showed that as to resistant material(R15), the activities of POD, CAT, SOD, APX increased and PAL kept stable in sheaths, in leaves the activity of POD, CAT and APX increased, SOD, PAL decreased. As to high susceptible material(478), the activities of POD and CAT increased in both sheaths and leaves, SOD increased in leaves but decreased in sheathes, both PAL and APX had no striking change. Generally speaking, the POD and CAT activities of maize were positively related to its resistance. Experimental results suggested that these defense enzymes functioned in differential areas and courses in plant accomplished defense reactions.