H_2O_2 参与棉疫病菌90kD蛋白激发子诱导的烟草过敏反应和系统获得抗性  

H_2O_2 Is Involved in Hypersensitive Response and Systemic Acquired Resistance Induced by the 90 kD Protein Elicitor of Phytophthora boehmeriae

作　　者：王源超[1] 张正光[1] 李俊[1] 安成才[2] 陈章良[2] 郑小波[1] 

机构地区：[1]南京农业大学植物保护学院,南京210095 [2]北京大学生命科学学院,北京100871

出　　处：《植物生理与分子生物学学报》2003年第3期185-191,共7页Journal Of Plant Physiology and Molecular Biology

基　　金：国家自然科学基金项目 (No .3 9970 478和 3 0 2 70 865 );教育部科学技术研究重点项目 (No .0 10 98)资助

摘　　要：野生型烟草Bel W3叶片经棉疫病菌 90kD蛋白激发子处理后 ,处理叶及其上位叶在 2 4h内均发生 2次氧化迸发产生H2 O2 ,且第二次H2 O2 迸发高峰期同时出现 ,均出现在第 12小时 ,处理部位细胞死亡高峰期比第二次H2 O2 迸发高峰期滞后 8h。引起过敏反应剂量的激发子诱发反义抑制抗坏血酸过氧化物酶anti APX烟草的过敏性坏死枯斑比野生型的大而且出现得早 ;不能诱发野生型烟草HR的剂量可以诱导anti APX烟草发生HR。经激发子处理后anti APX烟草对烟草疫霉 (Phytophthoranicotianae)和TMV产生的诱导抗性比其野生型高。上述结果表明 ,H2 O2 可能是一种重要的信号分子 ,在棉疫病菌 90kD蛋白激发子诱发烟草的HR和SAR中具有重要作用 ,但可能不是一种可以系统移动的信号分子。The role of H 2O 2 from the oxidative burst of tobacco leaves induced by 90 kD protein elicitor purified from the culture filtrate of Phytophthora boehmeriae in the hypersensitive response (HR) and systemic acquired resistance (SAR) of tobacco was studied. The elicitor induced a strong, biphasic H 2O 2 burst in treated leaf and the first untreated leaf. The kinetics was biphasic: phaseⅠ peaked 3 h and phaseⅡ 12 h after the treatment (Fig.3). The elicitor caused HR cell death of which the peak lagged behind the second H 2O 2 burst by 8 h (Figs.1 & 3). It has been shown recently that during the interaction of plants with pathogens, the expression of ROS detoxifying enzymes such as ascorbate peroxidase (APX) is suppressed, suggesting that this suppression might enhance H 2O 2 production. To examine further the role of H 2O 2 in HR cell death and SAR, The HR and SAR induced by elicitor were studied in antisense APX tobacco. Anti APX transgenic plants with reduced capability to detoxify H 2O 2 were found to be more sensitive than wild type plants to the elicitor. They exhibited HR cell death in response to low dosages of elicitor that did not trigger the activation of HR cell death in plants (Fig.4). And the transgenic plants were more resistant to tobacco black shank fungus, P.nicotianae , and TMV than the control plants after being induced by the elicitor (Figs.5 & 6). The results provide direct genetic evidence for H 2O 2 acting as an important signal molecule mediating elicitor induced HR cell death and SAR.

关 键 词：激发子 过敏反应 过氧化氢 系统获得抗性 烟草 

分 类 号：S435.72[农业科学—农业昆虫与害虫防治]