United States Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Philadelphia, Pennsylvania 19118.
Plant Physiol. 1989 Jan;89(1):5-9. doi: 10.1104/pp.89.1.5.
Bacterial exopolysaccharide (EPS) was extracted from infected leaves of several host plants inoculated with phytopathogenic strains of Pseudomonas syringae pathovars. Extraction was by a facilitated diffusion procedure or by collection of intercellular fluid using a centrifugation method. The extracted EPS was purified and characterized. All bacterial pathogens which induced watersoaked lesions on their host leaves, a characteristic of most members of this bacterial group, were found to produce alginic acid (a polymer consisting of varying ratios of mannuronic and guluronic acids). Only trace amounts of bacterial EPS could be isolated from leaves inoculated with a pathovar (pv. syringae) which does not induce the formation of lesions with a watersoaked appearance. Guluronic acid was either present in very low amounts or absent in the alginic acid preparations. All bacterial alginates were acetylated (7-11%). Levan (a fructan) was apparently not produced as an EPS in vivo by any of the pathogens tested.
从接种了丁香假单胞菌致病性菌株的几种寄主植物的感染叶片中提取细菌胞外多糖 (EPS)。提取方法是通过促进扩散程序或使用离心法收集细胞间液。提取的 EPS 经过纯化和表征。所有诱导寄主叶片水渍病变的病原菌，这是该细菌群大多数成员的特征，都被发现产生了海藻酸（一种由不同比例的甘露糖醛酸和古洛糖醛酸组成的聚合物）。从接种了不诱导出现水渍状病变的致病性菌株（ pv. syringae ）的叶片中只能分离出痕量的细菌 EPS。海藻酸制剂中要么甘露糖醛酸含量非常低，要么不存在。所有细菌海藻酸盐都乙酰化（7-11%）。在体内，测试的所有病原体似乎都没有产生作为 EPS 的莱凡（一种果聚糖）。
