title: Comparison of nodule induction in legume and actinorhizal symbioses: the induction of actinorhizal nodules does not involve ENOD40.
abstract: Two types of root nodule symbioses are known for higher plants, legume and actinorhizal symbioses. In legume symbioses, bacterial signal factors induce the expression of ENOD40 genes. We isolated an ENOD40 promoter from an actinorhizal plant, Casuarina glauca, and compared its expression pattern in a legume (Lotus japonicus) and an actinorhizal plant (Allocasuarina verticillata) with that of an ENOD40 promoter from the legume soybean (GmENOD40-2). In the actinorhizal Allocasuarina sp., CgENOD40-GUS and GmENOD40-2-GUS showed similar expression patterns in both vegetative and symbiotic development, and neither promoter was active during nodule induction. The nonsymbiotic expression pattern of CgENOD40-GUS in the legume genus Lotus resembled the nonsymbiotic expression patterns of legume ENOD40 genes; however, in contrast to GmENOD40-2-GUS, CgENOD40-GUS was not active during nodule induction. The fact that only legume, not actinorhizal, ENOD40 genes are induced during legume nodule induction can be linked to the phloem unloading mechanisms established in the zones of nodule induction in the roots of both types of host plants.
authors.affiliation: Equipe Rhizogenèse, UMR 1098, Institut de Recherche pour le Développement, 911 Avenue Agropolis, BP 64501, 34394 Montpellier cedex 5, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Santi
authors.forename: Uritza
authors.initials: U
authors.lastname: von Groll
authors.forename: Ana
authors.initials: A
authors.lastname: Ribeiro
authors.forename: Maurizio
authors.initials: M
authors.lastname: Chiurazzi
authors.forename: Florence
authors.initials: F
authors.lastname: Auguy
authors.forename: Didier
authors.initials: D
authors.lastname: Bogusz
authors.forename: Claudine
authors.initials: C
authors.lastname: Franche
authors.forename: Katharina
authors.initials: K
authors.lastname: Pawlowski
mesh_terms: D001483:Base Sequence; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000382:microbiology; D010944:Plants / Q000382:microbiology*; D011401:Promoter Regions, Genetic; D012689:Sequence Homology, Nucleic Acid; D013559:Symbiosis
chemical_list: D010940:Plant Proteins