title: Structural analysis of succinoglycan oligosaccharides from Sinorhizobium meliloti strains with different host compatibility phenotypes.
abstract: Sinorhizobium meliloti NRG247 has a Fix(+) phenotype on Medicago truncatula A20 and is Fix(-) on M. truncatula A17, and the phenotype is reversed with S. meliloti NRG185. As the succinoglycan was shown to impact host specificity, an analysis of the succinoglycan oligosaccharides produced by each strain was conducted. The symbiotically active succinoglycan trimeric oligosaccharides (STOs) from the two S. meliloti strains were compared by chromatography and mass spectrometry, and the analysis of the S. meliloti NRG247 oligosaccharides showed that this strain produces an abundance of STO trimer 1 (T1), containing no succinate (i.e., three nonsuccinylated repeats), yet the low-molecular-weight pool contained no nonsuccinylated monomers (potential repeats). This showed that STO T1 is likely to be the active signal on M. truncatula A20 and that the biosynthesis of the STOs is not a random polymerization of the monomer population. The results also suggest that the fully succinylated STO T7 is required for the infection of M. truncatula A17.
authors: North Dakota State University, Department of Plant Sciences, Fargo, North Dakota, USA. senay.simsek@ndsu.edu
authors: Senay
authors: S
authors: Simsek
authors: Karl
authors: K
authors: Wood
authors: Bradley L
authors: BL
authors: Reuhs
mesh_terms: D058507:Host Specificity; D013058:Mass Spectrometry; D046913:Medicago truncatula / Q000382:microbiology*; D009844:Oligosaccharides / Q000737:chemistry* / Q000378:metabolism; D010641:Phenotype; D010935:Plant Diseases / Q000382:microbiology*; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000378:metabolism; D016962:Sinorhizobium meliloti / Q000737:chemistry / Q000145:classification / Q000502:physiology*
chemical_list: D009844:Oligosaccharides; D011135:Polysaccharides, Bacterial; C056779:succinoglycan