Figure 1.

Wortmannin Strongly Inhibits the Sequence-Specific Vacuolar Sorting Route.

(A) The concentration-dependent influence of the drug wortmannin on the secretion index of amy (white bars) and amy-spo (gray bars) in tobacco mesophyl protoplasts. Transcriptional control of the cargo proteins was driven by the 35S promoter of Cauliflower mosaic virus (pCaMV35S), and 3′ end processing and polyadenylation was controlled by the 3′ untranslated end of the nopaline gene (3′nos). Protoplasts were transfected with a constant amount (10 μg) of plasmid-encoded cargo molecule and distributed in equal portions, subject to different concentrations of wortmannin and incubated for 24 h after which cells and media were harvested. The concentration of the drug is given below each lane. The secretion index was calculated as the ratio between the extracellular and the intracellular amy activities (Phillipson et al., 2001).

(B) The concentration-dependent influence of the drug wortmannin on the secretion index of amy-spo in transgenic tobacco BY2 cells. Because of the very high secretion index at 33 μM wortmannin, a split y axis was used for this lane.