TMEM37 and infection: In contrast, the HDA6, an RPD3/HDA1-type deacetylase, acts as a general repressor of pathogen defense response by negatively regulating the histone acetylation and the expression of pathogen-responsive genes, including PR1/2 and WRKY38 in Arabidopsis with or without pathogen infection of the hemibiotrophic bacterial pathogen Pseudomonas syringae pv.