Anti-oxidant enzyme activities of resistant (Res C) and susceptible (Sus C) un-inoculated control plants compared with those of plants inoculated with the avirulent field population Mi-Vfield (Res/-Sus/Miavr) and with the virulent isolate SM2V (Res/Mivir). Superoxide dismutase (SOD—A,B), catalase (CAT—C,D), and ascorbate peroxidase (APX—E,F) activities are expressed as Units mg-1 prot. Protein extraction was carried out using roots 1 and 5 DAI and using leaves 1 DAI. Values are shown as means (n = 9) ± SD. Means coming from tissues of inoculated plants were separated from those of un-inoculated controls by a t-test; asterisks indicate significant difference (*p < 0.05; **p < 0.01).