Figure 1.

The hydroxy fatty acid t-DHSA elicits H₂O₂ in abraded and conditioned cucumber hypocotyl segments, and enhances H₂O₂ elicitation of a polymeric fungal elicitor. Three batches each of 10 conditioned segments were either left as a control (•) or induced with 100 μm t-DHSA (▪ and ▵). One of the t-DHSA batches and the control batch received fungal elicitor (10 μg mL⁻¹) 2.5 h after the t-DHSA application (arrows). Values from another control batch run in parallel without any elicitor were subtracted. The elicitor activity of t-DHSA is shown as distance A. The factor for enhancement of the fungal elicitor activity caused by lipids was defined as division of distance B by distance C. In the above example, a 6-fold enhancement was calculated.