MAPK1 and infection: The results of inhibiting the ERK signal using PD at low (1 μM) and high (10 μM) concentrations to determine the effects on the TiLV concentrations revealed that pretreatment with a low PD concentration significantly reduced the viral RNA copies at 3 days post-infection (dpi) (4.84 ± 0.05) compared to the untreated TiLV-infected cells (5.24 ± 0.08) (Figure 5).