Clarifying the mechanism on systemic acquired resistance in Japanese birch plants infected with a canker-rot fungus, Inonotus obliquus

对日本桦树8号试管苗在真菌侵染早期感染桦褐孔菌IO-U1菌株的真菌侵染特异性蛋白进行了检测和鉴定。结果发现，感染该真菌的8号植株发生了氧化猝发和系统获得性抗性的保护反应。此外，对感染IO-U1菌株的8号和东北两种试管苗进行了解剖和组织化学观察。结果表明，酚类化合物及其聚合体的沉积和腐烂周皮的形成抑制了两种病原菌侵染植株的菌丝生长。此外，对8号植株产生的过氧化物酶进行了同工酶分析。结果表明，感染植株的过氧化物酶同工酶是酚类化合物聚合的专一性酶。此外，还用蛋白质组学方法研究了人工处理系统获得性抗性诱导化合物水杨酸的8号植株是否发生了系统获得性抗性。结果表明，8号试管苗喷施水杨酸后，诱导了植株的SAR。此外，真菌侵染和水杨酸处理对试管苗产生抗性的机制也不同。

The fungal infection specific proteins were detected and identified for the Japanese birch plantlets No.8 infected with a canker-rot fungus of birch trees, Inonotus obliquus IO-U1 strain at the early stage of their fungal infection. As a result, it was found that oxidative burst and systemic acquired resistance occur as the protective reactions in the plantlets No.8 infected with the fungus. In addition, anatomical and histochemical observations were performed for the two kinds of plantlets, No.8 and Tohoku, infected with IO-U1 strain. Consequently, it was suggested that deposition of phenolic compounds and their polymerized substance, and the formation of suberized necrophylactic periderm inhibit the growth of the fungal hyphae in the two kinds of plantlets infected with the fungus. Furthermore, isozyme analysis of the peroxidases produced in the plantlets No.8 was carried out. In consequence, it was indicated that the peroxidase isozymes of the infected plantlets are specialized for polymerization of phenolic compounds. Moreover, it was investigated by using proteome analysis whether systemic acquired resistance (SAR) occurs in the plantlets No.8 to which the SAR-inducing compound, salicylic acid was artificially administered. As a result, it was indicated that administration of salicylic acid to the plantlets No.8 induces SAR in the plantlets. In addition, it was suggested that the occurring resistance mechanisms are different between the case of the fungal infection and that of administration of salicylic acid to the plantlets.