STRUCTURAL DETERMINATION OF THE LPS FROM RHIZOBIUM

根瘤菌 LPS 的结构测定

• 批准号: 3296706
• 负责人: RUSSELL W CARLSON
• 金额: $ 9.86万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-06-01 至 1991-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3296706
• 关键词: Leguminoseae; Rhizobiaceae; bacterial genetics; bacterial polysaccharides; carbohydrate structure; gas chromatography; gel filtration chromatography; genetic strain; gram negative bacteria; host organism interaction; lipopolysaccharides; mutant; nitrogen fixation; nuclear magnetic resonance spectroscopy; plant growth /development; symbiosis

The lipopolysaccharides (LPSs) from Gram-negative bacteria are important molecules in determining whether or not a strain of bacteria will be a successful pathogen or will be recognized and destroyed by the defense mechanisms of the host cell. Lipopolysaccharides from the nitrogen-fixing Rhizobium bacteria are also thought to play a crucial role in the symbiotic infection of their host legumes. If this proposal is approved the funds will be used to determine the structures of the LPSs from one strain each of R. trifolii (symbiont of clover), R. leguminosarum (the symbiont of pea) and R. phaseoli (the symbiont of bean). In order to determine if genes required for infection and nodulation (nod genes) affect the structure of the LPSs, these molecules from one or two well defined symbiotic mutants will be characterized. In the case of R. trifolii the nod genes of interest reside on a plasmid which is required for nodulation (the pSym). These genes require induction by a legume flavone so the LPSs from induced bacteria will also be characterized. Analysis of the LPS from an R. leguminosarum strain which lacks its own pSym but contains an R. trifolii pSym and nodulates clover will also determine if the pSym nod genes affect LPS structure. The LPS from a mutant of R. phaseoli will be characterized since it has already been shown that this mutation produces a defective LPS and that this defect is linked to a symbiotic defect in which infection threads are aborted. The LPS will be isolated by phenol/water extraction and gel-filtration chromatography. The polysaccharide portions of the LPSs will be isolated and their structures determined by composition, methylation and GC/MS analyses and by 1H- and 13C-n.m.r analyses.

革兰氏阴性杆菌的脂多糖(LPS)是 重要的分子决定一种菌株是否 细菌将成为一种成功的病原体，或者将被公认为 被宿主细胞的防御机制摧毁。 固氮根瘤菌脂多糖的研究 也被认为在共生感染中起着关键作用 它们的寄主豆类植物。如果这项提议获得批准，这些资金将 用于确定一株菌株的LPS的结构 三叶草(三叶草共生菌)、豆科三叶草(R.trifolii) 豌豆共生体)和菜豆共生体(R.phaseoli)。按顺序 确定感染和结瘤所需的基因(NOD 基因)影响LPS的结构，这些分子来自一种 或者将描述两个定义明确的共生突变体。在……里面 以三叶草为例，感兴趣的结瘤基因位于一个 结瘤所需的质粒(PSym)。这些基因 需要豆类黄酮的诱导，这样LPS才能从 细菌也将被定性。安徽省新城疫病毒内毒素的分析 该菌株缺乏自身的pSym，但含有 三叶草和结瘤三叶草也将决定是否 PSym nod基因影响内毒素结构。从一株突变体中提取的内毒素 小豆根腐病菌将被定性，因为它已经被证明 这种突变产生了有缺陷的内毒素，而这种缺陷 与一种共生缺陷有关，在这种缺陷中感染线程 中止。脂多糖将通过苯酚/水提取和 凝胶过滤层析。丹参中的多糖部分 LPS将被隔离，其结构由 组成、甲基化和GC/MS分析及1H-和 13C-n.m.r分析。