PR1 was first identified in tobacco, and its upregulation has been shown to enhance resistance to fungal and bacterial disease in Arabidopsis, rice, Solanum lycopersicum (tomato), Triticum aestivum (wheat), and apple (Cao et al., 1998; Chern et al., 2001, 2005; Friedrich et al., 2001; Fitzgerald et al., 2004; Lin et al., 2004; Makandar et al., 2006; Malnoy et al., 2007). Here, TMEM37 is linked to bacterial infectious disease.