title: Competition among symbiotic cyanobacterial Nostoc strains forming artificial associations with rice (Oryza sativa).
abstract: Competition among four symbiotically competent Nostoc strains, colonizing rice roots, was examined using hetR-DGGE (denaturing gradient gel electrophoresis) as strain identification. Although mixed in various combinations, only one strain at a time associated with the rice roots. Nostoc strain 8964:3 was the most competitive and our data suggest that its competitive fitness was dependent on rapid hormogonial spreading as displayed on agar plates. Furthermore, rice roots induced hormogonia in all tested Nostoc strains, but only Nostoc strain 9104 showed positive chemotaxis towards the root. Inhibition of growth of competing cyanobacterial strains was not apparent.
authors.affiliation: Department of Botany, Stockholm University, Lilla Frescati vägen 5, S-10691 Stockholm, Sweden. malin.nilsson@botan.su.se
authors.forename: Malin
authors.initials: M
authors.lastname: Nilsson
authors.forename: Ulla
authors.initials: U
authors.lastname: Rasmussen
authors.forename: Birgitta
authors.initials: B
authors.lastname: Bergman
mesh_terms: D002633:Chemotaxis; D004587:Electrophoresis, Agar Gel; D009586:Nitrogen Fixation; D046937:Nostoc / Q000145:classification* / Q000254:growth & development* / Q000502:physiology; D012275:Oryza / Q000382:microbiology*; D018517:Plant Roots / Q000382:microbiology*; D013559:Symbiosis