Department of Plant Pathology, Cornell University, Ithaca, New York 14850.
Plant Physiol. 1969 May;44(5):641-8. doi: 10.1104/pp.44.5.641.
Enzymes in culture filtrates of Rhizoctonia solani Kuhn grown using 4-day old or 20-day old bean (Phaseolus vulgaris L.) hypocotyl cell walls as a carbon source degraded xylan, galactan, galactomannan, araban, polygalacturonic acid, and carboxymethylcellulose. Extracts of lesions from R. solani infected plants, but not healthy plants, contained similar enzymatic activities. These enzyme sources readily solubilized cell wall constituents containing arabinose, galactose, and glucose from 4-day old, but not from 20-day old, bean cell walls. Analysis of cell walls prepared from infected plants revealed that the alterations in cell wall composition in the diseased host were limited largely to the immediate lesion areas and occurred during the early phases of pathogenesis. The cell walls of young susceptible bean seedlings could be degraded by R. solani enzymes, but the cell walls of older plants which are resistant to this pathogen were not susceptible to enzymatic destruction by the same enzyme preparation.
丝核菌（Rhizoctonia solani Kuhn）在 4 天或 20 天的菜豆（Phaseolus vulgaris L.）下胚轴细胞壁作为碳源生长时，其培养液中的酶可降解木聚糖、半乳糖、半乳甘露聚糖、阿拉伯聚糖、聚半乳糖醛酸和羧甲基纤维素。受丝核菌感染的植物病灶提取物中含有类似的酶活性，但健康植物中没有。这些酶源很容易从 4 天的菜豆细胞壁中溶解含有阿拉伯糖、半乳糖和葡萄糖的细胞壁成分，但不能从 20 天的菜豆细胞壁中溶解。对受感染植物细胞壁的分析表明，在患病宿主中，细胞壁组成的改变主要局限于邻近的病灶区域，并发生在发病的早期阶段。丝核菌的酶可以降解幼嫩易感的菜豆幼苗细胞壁，但对这种病原体具有抗性的较老植物细胞壁不容易被相同的酶制剂进行酶解破坏。
