Plant root exudates impact the hydrocarbon degradation potential of a weathered-hydrocarbon contaminated soil

  1. (PDF, 525 KB)
  2. Get@NRC: Plant root exudates impact the hydrocarbon degradation potential of a weathered-hydrocarbon contaminated soil (Opens in a new window)
DOIResolve DOI:
AuthorSearch for: ; Search for: ; Search for: ; Search for:
Journal titleApplied Soil Ecology
Pages5664; # of pages: 9
AbstractPhytoremediation is a promising low cost technology for the cleanup of contaminated sites. However, specific plants may promote degradation under one set of conditions but not under another, and knowledge limitations surrounding the mechanisms of phytoremediation hamper attempts at optimization. We addressed this issue by examining how exudates released by Elymus angustus (wildrye) and Medicago sativa (alfalfa), grown under hydrocarbon-stressed or non-stressed conditions, impacted the degradation potential of microbial communities in a weathered hydrocarbon-contaminated soil. Degradation potential was assessed using mineralization assays with 14C-labeled hydrocarbons (hexadecane, naphthalene, phenanthrene) followed by DGGE of microbial communities and quantitative-PCR of genes associated with hydrocarbon degradation. All root exudates repressed hydrocarbon mineralization in soil microcosms, with exudates from hydrocarbon-stressed wildrye having the least repressive impact. Changes in degradation potential were not associated with changes in the dominant microbial community structure or with significant shifts in general microbial abundance. Degradation was, however, associated with functional changes in microbial communities. Mineralization of polyaromatic hydrocarbons (PAH) was highly correlated with copy numbers of catechol 2,3 dioxygenase and naphthalene dioxygenase, two genes involved in PAH degradation. Both gene copy numbers and mineralization parameters were significantly impacted by exudate composition, with specific compounds associated with either increased (acetate, alanine) or decreased (malonate) degradative capacity. The success of a given phytoremediation treatment is likely influenced by the relative amount of these and similar compounds within root exudates. © 2011 Elsevier B.V.
Publication date
AffiliationNRC Biotechnology Research Institute; National Research Council Canada
Peer reviewedYes
NRC number53393
NPARC number19230300
Export citationExport as RIS
Report a correctionReport a correction
Record identifiera0b0394e-f43c-4279-926b-fa0ac17de9e5
Record created2012-03-06
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)