title: Genetic and genomic analysis in model legumes bring Nod-factor signaling to center stage.
abstract: The control of host-specificity in the Rhizobium-legume symbiosis has been a topic of long-standing interest to plant biologists. By the early 1990s, biologists had deciphered the chemical signals that trigger early symbiotic responses. Flavonoids from the plant root trigger bacterial gene expression and the production of lipo-chitooligosaccharide signals (called Nod factors) that are recognized by the plant host. Genetic differences between bacterial strains modify the oligosaccharide backbone, for example by the addition of sulfate, acetate or fucose, and simultaneously alter the host-specificity of the purified Nod factor and the bacterium. Recent studies have begun to reveal the genetic and molecular basis of Nod-factor perception in legumes, a signaling system that also controls plant interactions with mycorrhizal fungi.
authors.affiliation: Department of Plant Pathology, University of California, One Shields Avenue, Davis, California 95616, USA.
authors.forename: Brendan K
authors.initials: BK
authors.lastname: Riely
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Ané
authors.forename: R Varma
authors.initials: RV
authors.lastname: Penmetsa
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Cook
mesh_terms: D007887:Fabaceae / Q000235:genetics* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000378:metabolism*; D008954:Models, Biological; D012231:Rhizobium / Q000235:genetics; D015398:Signal Transduction; D013559:Symbiosis
chemical_list: D008070:Lipopolysaccharides; C092736:Nod factor, Rhizobium leguminosarum; C023023:lipid-linked oligosaccharides