title: Tolerance and biodegradation of m-toluate by Scots pine, a mycorrhizal fungus and fluorescent pseudomonads individually and under associative conditions.
abstract: The tolerance to, and degradation of m-toluate by Scots pine (Pinus sylvestris), a symbiotic mycorrhizal fungus (Suillus bovinus) and Pseudomonas fluorescens strains, with or without m-toluate-degrading capacity, was determined individually and in all symbiotic/associative plant-microbe combinations. Fungal survival on medium with m-toluate was increased in co-culture with the degradative bacterial strains on agar plates (up to 0.02%, w/v). When fungi were grown in mycorrhizal association with Scots pine seedlings in test-tube microcosms containing expanded clay pellets and growth media, the fungus was able to withstand m-toluate concentrations up to 2.0%, w/v in all treatments. The seedling tolerance remained unaltered regardless of the presence or absence of mycorrhizal fungi or biodegradative bacteria. Reduction in m-toluate levels was only detected in treatments inoculated with bacterial strains harbouring TOL catabolic plasmids. The plant and fungus, alone or in mycorrhizal symbiosis, were unable to cleave m-toluate. The presence of easily available plant-derived carbon sources did not impede m-toluate degradation by the bacteria in the mycorrhizosphere.
authors.affiliation: Department of Biosciences, University of Helsinki, Finland.
authors.forename: I
authors.initials: I
authors.lastname: Sarand
authors.forename: S
authors.initials: S
authors.lastname: Timonen
authors.forename: T
authors.initials: T
authors.lastname: Koivula
authors.forename: R
authors.initials: R
authors.lastname: Peltola
authors.forename: K
authors.initials: K
authors.lastname: Haahtela
authors.forename: R
authors.initials: R
authors.lastname: Sen
authors.forename: M
authors.initials: M
authors.lastname: Romantschuk
mesh_terms: D001487:Basidiomycota / Q000378:metabolism*; D001565:Benzoates / Q000378:metabolism* / Q000494:pharmacology; D001673:Biodegradation, Environmental; D032462:Cycadopsida / Q000378:metabolism* / Q000382:microbiology; D004352:Drug Resistance, Microbial; D008826:Microbial Sensitivity Tests; D018517:Plant Roots / Q000382:microbiology; D011548:Pseudomonadaceae / Q000378:metabolism*; D012988:Soil Microbiology; D013559:Symbiosis / Q000502:physiology*; D014197:Trees / Q000378:metabolism / Q000382:microbiology
chemical_list: D001565:Benzoates; C009503:3-toluic acid