串珠镰刀菌引起玉米穗粒腐病防御酶变化及其电镜观察(英文)  

Investigation on Histological Observation and Protective Enzyme Activities in Ear Rot of Maize(Zea mays L.) after Fusarium moniliforme Infection

作　　者：袁广胜[1] 赵茂俊[1] 张志明[1] 沈亚欧[1] 潘光堂[1] 

机构地区：[1]四川农业大学玉米研究所教育部作物基因资源与遗传改良重点实验室,雅安625014

出　　处：《植物病理学报》2011年第4期385-392,共8页Acta Phytopathologica Sinica

基　　金：supported by grants from the Natural Science Foundation of Sichuan Province,China(2006B012);The Natural National Science Foundation of China(30571173);The Program for Changjiang Scholars and Innovative Research Team in University of China(IRT0453)

摘　　要：对串珠镰刀菌（Fusarium moniliforme）侵染引起玉米穗粒腐病的防御酶活性变化和病原菌侵染过程进行研究。采用人工接菌的方法,分别对抗（Bt-1）、感（掖478）玉米材料进行接种,取抗、感材料间隔24 h的6个时间段接菌部位的苞叶组织,分析玉米植株感病后部分防御酶、同工酶谱的动态变化,并用扫描电镜对病原菌入侵植株过程进行组织病理学观察。扫描电镜观察发现,菌丝首先要经过1~3 d生长后,大约在72 h左右开始侵入气孔,并且随着时间的推移,侵入气孔的菌丝量逐渐增多。这说明病原菌是直接通过气孔侵入寄主苞叶组织。同时,玉米受串珠镰刀菌侵染后,苯丙氨酸解氨酶（PAL）和过氧化物酶（POD）的活性都是先上升后下降,在感病材料Ye478中PAL的活性要比抗病材料Bt-1中增加的更快、更高;同样对于POD来说,在感病材料Ye478中的活性要比抗病材料Bt-1中的高,但变化趋势在2个材料中相似;而丙二醛（MDA）的含量则相反,在感病材料Ye478中的活性要比抗病材料Bt-1中的低;对POD同工酶酶谱分析,2个材料都增加了3~4个条带,没有明显的区别,这说明玉米感病后会通过增加POD的活性来抵御外源病菌的侵入。总体而言PAL和POD活性水平与材料抗性呈负相关;MDA与材料抗性呈正相关关系。对玉米植株感病后防御酶活性变化的分析和病原菌入侵寄主的电镜观察结果,可为深入研究玉米穗粒腐病抗病机制和抗病育种提供参考。To further investigate the processes involved in maize ear rot upon infection by the fungus Fusarium moniliforme（FM）,the time-course infection was observed through scanning electron microscope（SEM） to demonstrate pathogen progression in maize bract,then the biochemical and physiological enzyme activities were analyzed in the two maize cultivars,Bt-1 and Ye478,completely resistant and significantly susceptible to FM respectively.Microscopic observations showed that FM produced hyphae development first and then penetrated host tissues through the stoma at approximately 72 h postinoculation（hpi）.Meanwhile,the phenylalanine ammonia-lyases（PAL） and the reactive oxygen species（ROS） such as peroxidase（POD） were increased promptly higher and faster in Ye478,comparing to that in resistant cultivar Bt-1.The content of malondialdehyde（MDA） was higher in Bt-1than Ye478.Finally,the patterns of POD isozyme changed drama-tically and increased three or four bands in both cultivars after infection.The results imply that the relationship between protective enzymes activity and resistant cultivars are negatively correlated,while there was a positive correlation between the content of MDA and resistance of the cultivars.Overall,the response to protective enzyme activities and histological observation might provide important bases to probe the resistant mechanisms,the alteration of metabolism and the breeding research upon the infection of FM in maize.

关 键 词：玉米 串珠镰刀菌 穗粒腐 组织病理学观察 防御酶活性 

分 类 号：S435.131[农业科学—农业昆虫与害虫防治]