title: Linkage between bacterial and fungal rhizosphere communities in hydrocarbon-contaminated soils is related to plant phylogeny.
abstract: Phytoremediation is an attractive alternative to excavating and chemically treating contaminated soils. Certain plants can directly bioremediate by sequestering and/or transforming pollutants, but plants may also enhance bioremediation by promoting contaminant-degrading microorganisms in soils. In this study, we used high-throughput sequencing of bacterial 16S rRNA genes and the fungal internal transcribed spacer (ITS) region to compare the community composition of 66 soil samples from the rhizosphere of planted willows (Salix spp.) and six unplanted control samples at the site of a former petrochemical plant. The Bray-Curtis distance between bacterial communities across willow cultivars was significantly correlated with the distance between fungal communities in uncontaminated and moderately contaminated soils but not in highly contaminated (HC) soils (>2000 mg kg(-1) hydrocarbons). The mean dissimilarity between fungal, but not bacterial, communities from the rhizosphere of different cultivars increased substantially in the HC blocks. This divergence was partly related to high fungal sensitivity to hydrocarbon contaminants, as demonstrated by reduced Shannon diversity, but also to a stronger influence of willows on fungal communities. Abundance of the fungal class Pezizomycetes in HC soils was directly related to willow phylogeny, with Pezizomycetes dominating the rhizosphere of a monophyletic cluster of cultivars, while remaining in low relative abundance in other soils. This has implications for plant selection in phytoremediation, as fungal associations may affect the health of introduced plants and the success of co-inoculated microbial strains. An integrated understanding of the relationships between fungi, bacteria and plants will enable the design of treatments that specifically promote effective bioremediating communities.
authors.affiliation: Biodiversity Centre, Institut de recherche en biologie végétale, Université de Montréal and Jardin botanique de Montréal, Montreal, Quebec, Canada.
authors.forename: Terrence H
authors.initials: TH
authors.lastname: Bell
authors.affiliation: 1] Biodiversity Centre, Institut de recherche en biologie végétale, Université de Montréal and Jardin botanique de Montréal, Montreal, Quebec, Canada [2] Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Nasr City, Egypt.
authors.forename: Saad
authors.initials: S
authors.lastname: El-Din Hassan
authors.affiliation: Biodiversity Centre, Institut de recherche en biologie végétale, Université de Montréal and Jardin botanique de Montréal, Montreal, Quebec, Canada.
authors.forename: Aurélien
authors.initials: A
authors.lastname: Lauron-Moreau
authors.affiliation: 1] Biodiversity Centre, Institut de recherche en biologie végétale, Université de Montréal and Jardin botanique de Montréal, Montreal, Quebec, Canada [2] Department of Soil Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Fahad
authors.initials: F
authors.lastname: Al-Otaibi
authors.affiliation: Biodiversity Centre, Institut de recherche en biologie végétale, Université de Montréal and Jardin botanique de Montréal, Montreal, Quebec, Canada.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Hijri
authors.affiliation: National Research Council Canada, Energy, Mining and Environment, Montreal, Quebec, Canada.
authors.forename: Etienne
authors.identifier: 0000000271123425
authors.initials: E
authors.lastname: Yergeau
authors.affiliation: Biodiversity Centre, Institut de recherche en biologie végétale, Université de Montréal and Jardin botanique de Montréal, Montreal, Quebec, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: St-Arnaud
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006838:Hydrocarbons / Q000378:metabolism*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D032108:Salix / Q000145:classification / Q000382:microbiology; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism
chemical_list: D021903:DNA, Ribosomal Spacer; D006838:Hydrocarbons; D012336:RNA, Ribosomal, 16S; D012987:Soil; D012989:Soil Pollutants