We then examined the effect of hac1/5 mutations on the pathogen-induced expression of several SA biosynthesis or accumulation-related genes, namely ICS1 (63), EDS5 (64), PAD4 (65) and GDG1 (66,67) as the induction of ICS1 and EDS5 by pathogen infection was known to be NPR1-independent (68–70). This evidence concerns the gene PADI4 and infection.