College of Resource, Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China.
Rice Research Institute of Sichuan Agricultural University, Chengdu, Sichuan 611130, P.R. China.
Can J Microbiol. 2020 Mar;66(3):186-193. doi: 10.1139/cjm-2019-0413. Epub 2019 Nov 21.
Lipopolysaccharide (LPS) is essential for successful nodulation during the symbiosis of rhizobia and legumes. However, the detailed mechanism of the LPS in this process has not yet been clearly elucidated. In this study, the effects of common bean seed exudates on the growth, lipopolysaccharide production, and lipopolysaccharide transport genes expression () of were investigated. exposed to exudates showed changes in LPS electrophoretic profiles and content, whereby the LPS band was wider and the LPS content was higher in treated with seed exudates. Exudates enhanced cell growth of in a concentration-dependent manner; exposed to higher doses of the exudate showed faster growth. Seven genes of were amplified and sequenced. Sequences of six genes, except for , were the same as those found in previously analyzed strains, while shared low sequence similarity with other strains. Exposure to the exudates strongly stimulated the expression of all genes. Approximately 6.7- () to 301-fold () increases in the transcriptional levels were observed after only 15 min of exposure to exudates. These results indicate that seed exudates affect the LPS by making the cell wall structure more conducive to symbiotic nodulation.
脂多糖（LPS）是根瘤菌和豆科植物共生过程中成功结瘤所必需的。然而，LPS 在这个过程中的详细机制尚未被清楚阐明。在本研究中，研究了菜豆种子分泌物对的生长、脂多糖产生和脂多糖转运基因表达的影响。暴露于分泌物的 LPS 电泳图谱和含量发生变化，其中用种子分泌物处理的 LPS 带更宽，LPS 含量更高。分泌物以浓度依赖的方式增强的细胞生长；暴露于更高剂量分泌物的表现出更快的生长。扩增并测序了 7 个的基因。除了之外，的 6 个基因序列与先前分析的菌株中的基因序列相同，而与其他菌株的序列相似度较低。暴露于分泌物强烈刺激所有基因的表达。暴露于分泌物仅 15 分钟后，转录水平增加了约 6.7-（）至 301 倍（）。这些结果表明，种子分泌物通过使细胞壁结构更有利于共生结瘤来影响 LPS。
