FIGURE 6.

Fate of ingested plant myrosinase activity in P. armoraciae. Levels of soluble plant myrosinase activity were analyzed in extracts prepared from intact Arabidopsis myb leaves and in the corresponding amount of digested leaf material (feces). In addition, plant myrosinase extracts were co-incubated with the corresponding feces extract (n = 5–6 per treatment). Myrosinase activity was determined by adding 4MSOB glucosinolate to each sample. After 30 min incubation, the reaction was stopped by boiling. Remaining glucosinolate substrate was quantified by LC-MS/MS. Myrosinase activity in intact leaves was compared with that in digested leaves and in the co-incubation treatment by paired Student’s t-tests, respectively (^∗∗p < 0.005; n.s., p > 0.05). Results of statistical analyses are shown in Supplementary Table 1.