甘蓝链格孢菌侵染对白菜保护酶活性和H2O2代谢的影响

 以白菜抗黑斑病苏州青自交系和感黑斑病短白梗自交系为材料，研究其接种甘蓝链格孢菌后保护酶活性及H₂O₂代谢的变化。结果显示，抗感病材料的多酚氧化酶（PPO）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）与接种前相比均升高，且抗病材料的PPO、SOD始终高于感病材料，CAT活性低于感病材料；接种后抗病材料苯丙氨酸解氨酶（PAL）活性升高，而感病材料的PAL活性降低；抗感病材料接种后过氧化物酶（POD）、H₂O₂均呈上升趋势，且抗病材料的H₂O₂能很快降至较低水平。由此表明：甘蓝链格孢菌侵染白菜后，抗病材料与感病材料相比，能生成较多的PAL和PPO抵抗病原菌的侵染，并能短时迸发H₂O₂刺激抗氧化酶活性升高，使植物体内H₂O₂处于相对较低的水平，降低活性氧伤害。

Effects of Alternaria brassicicola(Berkeley)Saccardo Infection on Activities of Protective Enzymes and H2O2 Metablism in Non-heading Chinese cabbage

Changes of protective enzymes and the content of H₂O₂ were studied after Alternaria brassicicola infection on two no-heading Chinese cabbage materials（Suzhouqing and Duanbaigeng）. Results showed that PPO activity, SOD activity and CAT activity were increased in both disease-resistant material and disease-susceptible material, and PPO activity, SOD activity in Suzhouqing was higher than that in Duanbaigeng after infection, while CAT activity was lower than that in Duanbaigeng. As to PAL activity it was increased in Suzhouqing but decreased in Duanbaigeng. POD activity and H₂O₂ content was increased in both Suzhouqing and Duanbaigeng after inoculation, and the content of H₂O₂ could be lowered quickly in disease-resistant line. Thus it could be considered that compared with disease-susceptible material, disease-resistant material was able to produce more PPO and PAL that may resist the infection of Alternaria brassicicola, and was able to produce more H₂O₂ in short time to promote antioxidant enzymes activities, which could maintain low ROS level and reduce the damage of ROS after innoculation.