Figure 4.

Oxo-C14-HSL does not induce resistance against B. cinerea or P. cucumerina BMM. Five-week-old Arabidopsis plants were untreated (A and E), pretreated with acetone (B and F), or 6 μm oxo-C14-HSL (C and G) for 3 d. Conidial suspensions were dropped onto detached leaves. Necrotic symptoms or lesion diameters were analyzed at 5 dpi. Classification of symptoms: I, healthy leaf; II, leaf necrotic at 25%; III, 50% of leaf surface show necrosis; IV, 75% necrotic surface; V, 100% of the leaf surface is necrotic. D, Necrotic symptoms caused by B. cinerea. H, Lesions caused by P. cucumerina BMM.