Figure 3.

The Signaling Pathway Leading from LPS Perception to NO Generation Involves Ca²⁺, CAM, and NOS.

LPS activation of NO is blocked by chelation of extracellular Ca²⁺ with 2 mM EGTA (J) and by inhibitors of Ca²⁺ channels (100 μM Gd³⁺; [B]), Arg-dependent NOS (200 μM l-NAME; [C] and [D]), and CaM (50 μM W7; [G] and [H]). Also shown are results with the W7 analog W5 at 50 μM (F), the l-NAME isomer d-NAME at 200 μM (K), and the K⁺ channel blocker TEA at 10 mM (L). In all cases, DAF-2DA was loaded into cells of the epidermal peels and fluorescence was measured after addition of LPS. For each treatment, fluorescence and bright-field images are shown. Results from several experiments are compiled in this figure; controls (i.e., application of LPS alone to wild-type epidermal peels) for each experiment are shown in (A), (E), and (I). Results from epidermal peels prepared from wild-type ([A] to [C], [E] to [G], and [I] to [L]) and dnd1 ([D] and [H]) plants are shown. Experiments were repeated at least two times; representative images are shown.