Three of them were analyzed by qRT-PCR during infection: ISOCHORISMATE SYNTHASE1 (ICS1, also known as SID2) which plays a major role in SA biosynthesis (Garcion et al., 2008; Huang et al., 2010), and, more upstream, ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) and PHYTOALEXIN DEFICIENT 4 (PAD4) which were reported as being important for plant immunity through both SA-dependent and -independent pathways (Bartsch et al., 2006; Cui et al., 2017). The gene discussed is PADI4; the disease is infection.