Plants were soil treated with a zoospore suspension of P. nicotianae, 2.5 mM BABA, or sterile DI water, and foliar inoculated with P. capsici a zoospore suspension as described above. At 12, 24, and 48 h post inoculation, leaf tissue was removed and immediately immersed in DAB solution (1 mg/mL) in 10 mM sodium phosphate buffer with Tween 20 (0.05% v/v) in a covered dish on a rocker platform at room temperature. After 4 h the DAB staining solution was replaced with bleaching solution (ethanol:acetic acid:glycerol 3:1:1) and boiled for 10 min to remove plant pigments [27]. Tissue was imaged using a compound microscope with a digital camera mounted using an eyepiece adapter (Nikon, Melville, NY).