Changes of protective substances and enzymes in non-heading Chinese cabbage after infection by downy mildew | 不结球白菜感染霜霉病菌后防御物质及酶的变化

Китайский. 采用不同霜霉病抗性的不结球白菜自交系，研究了其对霜霉病的抗性机制。结果表明：在接种病原菌前，不结球白菜健康叶片中木质索含量与霜霉病的抗性成正相关，几丁质酶与霜霉病抗性没有明显的相关性。接种后抗病材料叶片中的木质素含量呈现出快速上升、下降、再上升、再下降的趋势，分别在接种后24h和96h达到峰值；而感病材料变化缓慢，变化幅度小，在36h达到峰值。接种后抗病材料的几丁质酶变化迅速，且长时间处于高活性，在48h达到峰值；相比之下，感病材料的酶活性增高的幅度小，高活性维持时间短，在36h达到峰值。上述结果表明，叶片中的木质素含量和几丁质酶活性的动态变化，是植物抗性潜能被激活的结果，是诱导抗性机制的一部分。[著者文摘]

Английский. Inbred lines of non-heading Chinese cabbage with different resistance to downy mildew were conducted for studying the metabolism of resistance to downy mildew. As shown by the result, before the inoculation, the lignin contents in healthy leaves were positive correlated to the resistance to downy mildew of inbred lines of non-heading Chinese cabbage, while there was no obvious correlation between chitinase activities and the resistance to downy mildew of inbred lines. According to the results, after the inoculation, the lignin contents in resistant lines increased rapidly prior to decrease slowly, and then they increased again prior to decrease again, leading to two peaks at 24 h and 96 h after inoculation. The lignin contents in susceptible lines had a slow change with only one peak at 36 h after inoculation. The chitinase activities in resistant lines had a rapid change and a long time with high activities, resulting in a peak at 48 h after inoculation while the chitinase activities in susceptible lines had a slow change and a peak at 36 h after inoculation. The above results indicated that activation of resisted potential of plants led to the increase of lignin content and chitinase activities, which belonged to the metabolism of inducing resistance.