title: Cyanogenic Pseudomonas spp. strains are concentrated in the rhizosphere of alpine pioneer plants.
abstract: HCN producing bacteria have previously been isolated from alpine mineral soil and their ecophysiology was presumed to be associated with mineral weathering. Nevertheless, the high ecological patchiness of the alpine environment calls for an extensive and detailed analysis of the spatial distribution of HCN producing bacterial populations and their associated weathering traits. Our results of such an analysis showed that primarily the rhizosphere of pioneer plants was rich in HPPs, harbouring the most potent HCN producers. HCN production incidence and intensity were dependent on the plant-associated microhabitat and type of bedrock/mineral soil, however the HCN+ phenotype was not associated with one of the particular genotypes which we determined by BOX-PCR. In HPP isolates, HCN production most commonly co-occurred with the production of hydroxamate-type siderophores, but was less often associated with inorganic phosphate solubilization activity and the production of catechol-type siderophores. These observations indicate that a plant's physiotype, not species, provide physicochemical conditions that determine selective pressure, which enables the growth of Pseudomonas spp. with a random genotype, but phenotypically predetermined to increase mineral weathering via a particular combination of phosphate solubilization and iron complexation with siderophores and HCN.
authors.affiliation: Institute of Metagenomics and Microbial Technologies, Clevelandska ulica 19, 1000 Ljubljana, Slovenia; Department of Environmental Sciences, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia. Electronic address: tomaz.research@gmail.com.
authors.forename: Tomaž
authors.initials: T
authors.lastname: Rijavec
authors.affiliation: Institute of Metagenomics and Microbial Technologies, Clevelandska ulica 19, 1000 Ljubljana, Slovenia; Department of Environmental Sciences, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia; Remote Controlled Theranostic Systems Lab, Saratov State University, Astrakhanskaya 83, Saratov, Russian Federation. Electronic address: lapanje.ales@gmail.com.
authors.forename: Aleš
authors.initials: A
authors.lastname: Lapanje
mesh_terms: D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D017753:Ecosystem; D005838:Genotype; D006856:Hydrogen Cyanide / Q000737:chemistry / Q000378:metabolism*; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D009842:Oligopeptides / Q000378:metabolism; D010641:Phenotype; D010710:Phosphates / Q000737:chemistry / Q000378:metabolism; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology*; D010944:Plants / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D011549:Pseudomonas / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012231:Rhizobium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D058441:Rhizosphere; D017262:Siderophores / Q000737:chemistry / Q000378:metabolism; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D013557:Switzerland; D065929:Tundra
chemical_list: D004269:DNA, Bacterial; D009842:Oligopeptides; D010710:Phosphates; D017262:Siderophores; D012987:Soil; D006856:Hydrogen Cyanide; C042453:pyoverdin; D007501:Iron
keywords: Alpine oligotrophic environment; HCN; Mineral weathering; Pseudomonads; Rhizobacteria; Siderophores