부산대학교 도서관

Ethephon (2-chloroethylphosphonic acid), an ethylene-releasing compound, applied by spraying (3 mM) on apical leaves or pricking (0.2 M) fully expanded leaves of Gynura aurantiacaplants delayed symptom expression in plants inoculated with citrus exocortis viroid (CEV). Only the ethephon-pricked leaves accumulated the pathogenesis-related proteins PI and P2 originally found associated with citrus exocortis viroid (CEV) infection in this plant. No pathogenesis-related proteins appeared in the protected apical leaves until after the protection was overcome. Pathogenesis-related proteins have been implicated in resistance to pathogens. However, this ethephon-induced protection in G. aurantiacaplants was not correlated with detectable increases in the level of PI and P2 or any other protein in the protected leaves.