May play a role in plant immunity. Expressed in senescing leaves. Up-regulated in leaves during natural senescence. By ethylene, abscisic acid (ABA), beta-aminobutyric acid (BABA), spermine, dark and infection with the cucumber mosaic virus (CMV) (PubMed:11230571, PubMed:14666423, PubMed:22947164). Induced by infection with the fungal pathogen Botrytis cinerea (PubMed:23221759).