Figure 5

Quantitative qPCR measurement of the expression of TonB-dependent family receptor (TR99219|c0_g1) in nickel resistant and susceptible white birch (Betula papyrifera) treated with 1600 mg kg−1 of nickel. Expression was standardized using the housekeeping gene ef1a. Normalization was then performed against water controls (all values divided by water). *Significant differences were found using ANOVA (Tukey’s HSD multiple comparison analysis, P<0.05).