title: Bacterial Molecular Signals in the Sinorhizobium fredii-Soybean Symbiosis.
abstract: Sinorhizobium (Ensifer) fredii (S. fredii) is a rhizobial species exhibiting a remarkably broad nodulation host-range. Thus, S. fredii is able to effectively nodulate dozens of different legumes, including plants forming determinate nodules, such as the important crops soybean and cowpea, and plants forming indeterminate nodules, such as Glycyrrhiza uralensis and pigeon-pea. This capacity of adaptation to different symbioses makes the study of the molecular signals produced by S. fredii strains of increasing interest since it allows the analysis of their symbiotic role in different types of nodule. In this review, we analyze in depth different S. fredii molecules that act as signals in symbiosis, including nodulation factors, different surface polysaccharides (exopolysaccharides, lipopolysaccharides, cyclic glucans, and K-antigen capsular polysaccharides), and effectors delivered to the interior of the host cells through a symbiotic type 3 secretion system.
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida de Reina Mercedes, 6, 41012 Sevilla, Spain. jlopez@us.es.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: López-Baena
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida de Reina Mercedes, 6, 41012 Sevilla, Spain. rsainz@us.es.
authors.forename: José E
authors.initials: JE
authors.lastname: Ruiz-Sainz
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Profesor García González, 1, 41012 Sevilla, Spain. rcarvaj@us.es.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Rodríguez-Carvajal
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida de Reina Mercedes, 6, 41012 Sevilla, Spain. jvinar@us.es.
authors.forename: José M
authors.initials: JM
authors.lastname: Vinardell
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D055170:Plant Root Nodulation; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D042181:Sinorhizobium fredii / Q000378:metabolism / Q000502:physiology*; D013025:Glycine max / Q000382:microbiology*; D013559:Symbiosis; D000069296:Type III Secretion Systems
chemical_list: D001426:Bacterial Proteins; D011135:Polysaccharides, Bacterial; D000069296:Type III Secretion Systems
keywords: Bradyrhizobium; K-antigen polysaccharide; Nod factors; Sinorhizobium fredii; cyclic glucans; effector; exopolysaccharide; lipopolysaccharide; soybean; type 3 secretion system