Effects of recombinant NvKSPI-1 and NvKSPI-2 on the PPO activation (A) and PO activity (B) of hemolymph of M. domestica pupae. (A) Screened hemolymph was incubated with TBS alone, or TBS/M. luteus, NvKSPI-1/M. luteus, NvKSPI-2/M. luteus, BSA/M. luteus, GST/M. luteus, PTU/M. luteus in TBS for 20 min at 25 °C. PPO activation was assayed using l-dopamine as a substrate, as described in Materials and Methods. (B) Screened hemolymph was incubated with M. luteus in TBS for 10 min at 25 °C, and then incubated with TBS, NvKSPI-1, NvKSPI-2, BSA, GST, or PTU for 10 min at 25 °C. PO activity was assayed using l-dopamine as a substrate, as described in Materials and Methods. All values in the figure are represented as mean ± standard deviation. Bars labeled with different letters are significantly different (one-way ANOVA followed by LSD test, p < 0.05).