Figure 3.

(A) PPO activity, (B) CAT activity, and (C) POD activity of Medicago sativa inoculated with Rhizophagus intraradices (AM), infected with Phoma medicaginis (P+), and infested with Acyrthosiphon pisum (A+), or non-inoculated with R. intraradices (NM), non-infected with P. medicaginis (P−), and non-infested with A. pisum (A−). All values are the mean ± SEM of three biological replicates. Different letters above pairs of bars indicate a significant difference in the comparison at p < 0.05. In (A) asterisks indicate a significant difference between P−A− and P− +, or P+A− and P+A+, as determined by Tukey’s HSD test. SEM, standard error of the mean; PPO, polyphenol oxidase; CAT, catalase; POD, peroxidase.