title: Early symbiotic responses induced by Sinorhizobium meliloti iIvC mutants in alfalfa.
abstract: A mutation in the ilvC gene of Sinorhizobium meliloti 1021 determines a symbiotically defective phenotype. ilvC mutants obtained from different S. meliloti wild-type strains are able to induce root hair deformation on alfalfa roots and show variable activation of the common nodulation genes nodABC. All of these mutants are noninfective. The presence of extra copies of nodD3-syrM in an IlvC- background does not promote nod expression but allows the detection of low levels of Nod factor production. The sulphation of the Nod factor metabolites, however, is not affected. Furthermore, IlvC- strains induce a specific pattern of starch accumulation on alfalfa roots as well as of early nodulin expression. Hence, the pleiotropic action of the ilvC gene in S. meliloti may reveal novel complexities involved in the symbiotic interaction.
authors.affiliation: Instituto de Bioquímica y Biologia Molecular, Universidad Nacional de La Plata, Facultad de Ciencias Exactas, Argentina.
authors.forename: J C
authors.initials: JC
authors.lastname: López
authors.forename: D H
authors.initials: DH
authors.lastname: Grasso
authors.forename: F
authors.initials: F
authors.lastname: Frugier
authors.forename: M D
authors.initials: MD
authors.lastname: Crespi
authors.forename: O M
authors.initials: OM
authors.lastname: Aguilar
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics; D005798:Genes, Bacterial; D050540:Ketol-Acid Reductoisomerase; D000455:Medicago sativa / Q000166:cytology / Q000378:metabolism / Q000382:microbiology*; D008868:Microtubule Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D016962:Sinorhizobium meliloti / Q000201:enzymology / Q000235:genetics*; D013559:Symbiosis
chemical_list: D008868:Microtubule Proteins; D000429:Alcohol Oxidoreductases; D050540:Ketol-Acid Reductoisomerase