To further investigate the dependency of 3OC8-HSL-enhanced resistance on SA signaling, we applied 3OC8-HSL to the bottom-layer medium of the following plants grown in a sterile systemic hydroponic system prior to PstDC3000 infection: wild-type Arabidopsis Col-0, the NPR1-deficient mutant npr1–1, and NahG transgenic plants (NahG). Here, NPR1 is linked to infection.