Arabidopsis pectin methylesterase (PME) and β‐1,3‐glucanase (BGL) are known to regulate plasmodesmata functions during virus infection in plants (Dorokhov et al., 1999; Chen et al., 2000; Iglesias & Meins, 2000; Bucher et al., 2001). Here, CSTB is linked to viral infectious disease.