Fig. 5

Polyphenol oxidase activity was identified in different treatments in the rhizosphere and nonrhizosphere

Control with (Piri) or without (Control) P. indica inoculation; Phe contaminated soil with (Piri+Phe) or without (Phe) P. indica inoculation; Cd contaminated soil with (Piri+Cd) or without (Cd) P. indica inoculation; Phe-Cd co-contaminated soil with (Piri+Cd + Phe) or without (Cd + Phe) P. indica inoculation. M. sativa was planted in all treatments. Each value of fresh weight is the mean of three replicates. Error bars show standard error. For the Control and Piri, Cd and Piri+Cd, Phe and Piri+Phe, Phe + Cd and Piri+Phe + Cd, the adding of P. indica spores significantly increases the polyphenol oxidase activity both in the rhizosphere and nonrhizosphere compared with that in the treatment without P. indica inoculation. Different letters (a-d) in the columns indicate significant difference in polyphenol oxidase activity between treatments according to the Duncan’s Multiple Range Test (P < 0.05)