摘要
毛白杨(Populus tomentosa Carr)叶片在受到马格栅锈菌(Melompo-sora magnusiana Wagner)侵染以后,用分光光度法和聚丙烯酰胺凝胶电泳测定结果均证明:在侵染初期,叶片中的过氧化物酶和多酚氧化酶活性均明显上升。在孢子堆出现前后,酶活性增加达到高峰,以后又趋下降。同时,这两种酶的同功酶谱带形式也发生了明显的改变。 这些新增加的酶活性,主要来自寄主对病原生物侵染的反应,其中包括侵染所引起的寄主组织的“老化”反应。病原菌的孢子和菌丝中这两种酶活性极低,对病变中酶活性变化率影响极小。 病组织中的多酚氧化酶和过氧化物酶与正常叶片中的酶相比较,在某些酶学性质上(诸如温度曲线,最适pH值,底物的亲和力,热稳定性和对某些抑制剂的反应)也发生了相应的变化。 病斑对于周围绿色组织中酶活性的影响,随着距离的增加而减少。但到6-8mm处仍有明显的反应。 对实验条件作了合理的选择。
In leaves of Populus tomentosa Carr. infected by Melampsora magnu-siana Wagner activities of the peroxidase and polypkenoloxidase Were increased obviously in initial stage. The activities of enzymes were determined by polyacrylamide gel elcctrophoreses and spectrophotometry . It does achieve the top of curve at the time about the uredia occur, and then decline. Also, the isozyme patterns of peroxidase and polypheuol-oxidase in infected leaves differ markedly from those in healthy leaves used as control.The enhanced enzyme activity is due to the reaction of host to the infection, including the aging phenomenon of host tissues caused by the infections of parasite. Peroxidase and polyphenoloxidase activity in spores and mycelia is extremely low. So there is little influence on the total enzyme activity.The effects of infected spot on enzyme activity of adjacent green tissues are obvious. Although the effects decreased with distance, the effects were still distinct in the area of 6-8mm from the spot.As compared with the control, some variations changes in temperature curve optimum pH. substrate, affinity inhibition reaction of some inhibitor and heat stability of peroxidase and polyphonolox idase in disea-
