title: Adsorption of tumorigenic Agrobacterium tumefaciens cells to susceptible potato tuber tissues.
abstract: Cells of tumorigenic Agrobacterium tumefaciens strain B6 were labeled with [35S]methionine and used to estimate bacterial adsorption to potato tuber discs. After 10 min at pH 7.2, about 5 X 10(5) bacteria adsorb to each 9.0-mm disc. Lengthening the incubation period to 90 min increases adsorption to about 11 X 10(5) bacteria per disc. Bacterial adsorption is reduced under both alkaline and acid pH conditions and increases 2.3-fold if the number of bacterial cells in the inoculum is doubled. Adsorption is increased if citrus pectin, polygalacturonic acid, or demethylated pectin is included in the inoculum; methylated polygalacturonic acid is inactive. The activity of citrus pectin is abolished, however, if the compound is applied to the discs as a pretreatment and then removed prior to inoculation. Lipopolysaccharide preparations from five of six A. tumefaciens strains have no effect on bacterial adsorption. The sixth preparation, from nontumorigenic strain NT-1, reduces adsorption by about 20%.
mesh_terms: D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D010368:Pectins / Q000494:pharmacology; D010941:Plant Tumors / Q000382:microbiology*; D010944:Plants / Q000382:microbiology*; D012231:Rhizobium / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D014675:Vegetables
chemical_list: D008070:Lipopolysaccharides; D010368:Pectins; C003181:polygalacturonic acid