FIG. 3.

Numbers of probe-positive rhizosphere bacteria (●) or endophytes (○) present in F. arundinacea in response to increasing creosote concentrations in soil. F. arundinacea was planted in garden soil mixed with five concentrations (0, 5, 10, 20, and 40%) of soil heavily contaminated with creosote (43 g C₁₀ to C₅₀ aliphatic hydrocarbons and 11 g of polycyclic aromatic hydrocarbons kg of soil⁻¹). Plants were grown in replicate pots (n = 5) for 7 weeks in a greenhouse, and the genotype prevalence in the bulk soil and root interior was determined. Each point is the average of five replicates. The error bars are obscured by the symbols.