title: Depolarization of alfalfa root hair membrane potential by Rhizobium meliloti Nod factors.
abstract: Although much is known about the bacterial genetics of early nodulation, little is known about the plant cell response. Alfalfa root hair cells were impaled with intracellular microelectrodes to measure a membrane potential depolarizing activity in Rhizobium meliloti cell-free filtrates, a plant response dependent on the bacterial nodulation genes. The depolarization was desensitized by repeated exposure to factors and was not observed in a representative nonlegume. A purified extracellular Nod factor, NodRm-IV(S), caused membrane potential depolarization at nanomolar concentrations. This rapid single-cell assay provides a tool for dissecting the mechanisms of host cell response in early nodulation.
authors.affiliation: Department of Biological Sciences, Stanford University, Stanford CA 94305, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Ehrhardt
authors.forename: E M
authors.initials: EM
authors.lastname: Atkinson
authors.forename: S R
authors.initials: SR
authors.lastname: Long
mesh_terms: D008070:Lipopolysaccharides / Q000494:pharmacology*; D000455:Medicago sativa / Q000166:cytology / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D016962:Sinorhizobium meliloti / Q000502:physiology
chemical_list: D008070:Lipopolysaccharides; C092082:Nod factor IV, Rhizobium meliloti