title: Bradyrhizobium japonicum mutants defective in cyclic beta-glucan synthesis show enhanced sensitivity to plant defense responses.
abstract: Susceptibility of the nitrogen-fixing soybean symbiont Bradyrhizobium japonicum to inducible plant defense metabolites such as phytoalexin and H2O2, was investigated. On the wild-type strain USDA 110 the soybean phytoalexin, glyceollin, showed bacteriostatic activity. Viable bacteria isolated from intact nodules were adapted to glyceollin. H2O2 in physiological concentrations did not affect wild-type bacteria. B. japonicum mutants defective in the biosynthesis of cyclic beta-(1-->3)-(1-->6)-glucans showed higher susceptibility to both phytoalexin and H2O2.
authors.affiliation: Botanisches Institut der Universität, München, Germany. amithoef@botanik.biologie.uni-muenchen.de
authors.forename: A
authors.initials: A
authors.lastname: Mithöfer
authors.forename: A A
authors.initials: AA
authors.lastname: Bhagwat
authors.forename: D L
authors.initials: DL
authors.lastname: Keister
authors.forename: J
authors.initials: J
authors.lastname: Ebel
mesh_terms: D001578:Benzopyrans / Q000494:pharmacology*; D020369:Bradyrhizobium / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D005936:Glucans / Q000096:biosynthesis / Q000235:genetics*; D010936:Plant Extracts / Q000494:pharmacology*; D036343:Pterocarpans; D012717:Sesquiterpenes; D013025:Glycine max / Q000382:microbiology / Q000502:physiology; D013559:Symbiosis; D013729:Terpenes / Q000494:pharmacology; D047071:beta-Glucans; D000094162:Phytoalexins
chemical_list: D001578:Benzopyrans; D005936:Glucans; D010936:Plant Extracts; D036343:Pterocarpans; D012717:Sesquiterpenes; D013729:Terpenes; D047071:beta-Glucans; C089202:cyclic (1-6)-(1-3)-glucan; C017343:glyceollin; D000094162:Phytoalexins