PADI4 and infection: The SA biosynthesis gene ICS1 (Isochorismate synthase 1), the SA biosynthesis regulatory genes EDS1 (Enhanced disease susceptibility 1) and PAD4 (Phytoalexin-deficient 4), and the PR protein genes PR1 and PR2 (Maleck et al., 2000) were studied in the infected leaves in both CsUGT87E7-silenced and control tea plants after pathogen infection.