TMEM37 and bacterial infectious disease: Furthermore, the SNARE SYP132 mediates secretion of antimicrobial PR1 peptides to the apoplast in response to bacterial infection (Kalde et al., 2007; Figure 1, G and H and Supplemental Figure S1H), so the downregulation of SYP132 expression by auxin would suppress PR1 secretion, inhibiting PR1-associated antimicrobial activity and host defense signaling (Jones and Dangl, 2006).