Department of Biology, Faculty of Science, Kagoshima University, Kagoshima 890, Japan.
Appl Environ Microbiol. 1980 Feb;39(2):297-301. doi: 10.1128/aem.39.2.297-301.1980.
An extrinsic substance (ES-6000) was isolated from the periplasmic space of Rhizobium trifolii (strain 4S) cells by osmotic shock, using a high-density sucrose solution. This substance promoted infection thread formation in root hairs of white clover when inoculated together with the infectious strain (4S). However, ES-6000 obtained from another rhizobial species and from strain A1, which is a noninfectious mutant strain obtained from strain 4S, did not have this effect. The promoter in the ES-6000 from strain 4S is a relatively small molecule since it passed through a hollow-fiber membrane (molecular weight, 6,000). This substance was also recognized as an R(f) 0.1 fraction by paper chromatography. Sucrose was effective in promoting nodulation and root elongation.
从 Rhizobium trifolii（菌株 4S）细胞的周质空间中通过渗透压休克用高浓度蔗糖溶液分离出一种外源性物质（ES-6000）。当与感染菌株（4S）一起接种时，该物质促进了白三叶草根毛中的侵染线形成。然而，从另一种根瘤菌物种和菌株 A1（从菌株 4S 获得的非感染突变体菌株）中获得的 ES-6000 没有这种作用。4S 菌株 ES-6000 中的启动子是一种相对较小的分子，因为它通过了中空纤维膜（分子量为 6000）。该物质也被纸层析法鉴定为 R(f)0.1 馏分。蔗糖对促进结瘤和根伸长有效。
