title: How legumes recognize rhizobia.
abstract: Legume plants have developed the capacity to establish symbiotic interactions with soil bacteria (known as rhizobia) that can convert N2 to molecular forms that are incorporated into the plant metabolism. The first step of this relationship is the recognition of bacteria by the plant, which allows to distinguish potentially harmful species from symbiotic partners. The main molecular determinant of this symbiotic interaction is the Nod Factor, a diffusible lipochitooligosaccharide molecule produced by rhizobia and perceived by LysM receptor kinases; however, other important molecules involved in the specific recognition have emerged over the years. Secreted exopolysaccharides and the lipopolysaccharides present in the bacterial cell wall have been proposed to act as signaling molecules, triggering the expression of specific genes related to the symbiotic process. In this review we will briefly discuss how transcriptomic analysis are helping to understand how multiple signaling pathways, triggered by the perception of different molecules produced by rhizobia, control the genetic programs of root nodule organogenesis and bacterial infection. This knowledge can help to understand how legumes have evolved to recognize and establish complex ecological relationships with particular species and strains of rhizobia, adjusting gene expression in response to identity determinants of bacteria.
authors.affiliation: a Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT-La Plata, CONICET , La Plata , Argentina.
authors.forename: Virginia Dalla
authors.initials: VD
authors.lastname: Via
authors.affiliation: a Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT-La Plata, CONICET , La Plata , Argentina.
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Zanetti
authors.affiliation: a Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT-La Plata, CONICET , La Plata , Argentina.
authors.forename: Flavio
authors.initials: F
authors.lastname: Blanco
mesh_terms: D007887:Fabaceae / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D008954:Models, Biological; D053472:Nod Signaling Adaptor Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012230:Rhizobiaceae / Q000378:metabolism*; D053204:Root Nodules, Plant / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D015398:Signal Transduction; D013045:Species Specificity; D013559:Symbiosis / Q000235:genetics / Q000502:physiology*; D059467:Transcriptome
chemical_list: D005656:Fungal Proteins; D053472:Nod Signaling Adaptor Proteins; D010940:Plant Proteins
keywords: Exopolysaccharide; lipolysaccharide; nitrogen fixation; nod factor; nodulation; receptors