Figure 8.

Transient expression of constitutively active phosphomimicking forms SlMKK2^DD and SlMKK4^DD in Nicotiana benthamiana resulted in increased disease resistance against B. cinerea. Disease symptom (A), lesion size (B) and expression of defense genes (C) in SlMKK2^DD- and SlMKK4^DD-infiltrated plants. Opposite part of the leaves infiltrated with SlMKK2^DD and SlMKK4^DD constructs was inoculated by dropping spore suspension (2 × 10⁵ spores/mL) of B. cinerea. Lesion sizes were measured at 5 days after inoculation on a minimum of 10 leaves in each experiment. Expression of defense genes was analyzed by qRT-PCR at indicated times and relative expression levels were calculated by comparing with the corresponding values at 0 hr (as a control) after inoculation. Data presented in (C) are the means ± SD from three independent experiments and different letters above the columns indicate significant differences at p < 0.05 level.