Environmental factors and phytohormones enhancing expression of α-momorcharin gene in Momordica charantia

Ribosome-inactivating proteins (RIPs), a type of defensive chemicals, play key roles in host defense mechanisms against foreign pathogenic invaders and plant stress resistance. Alpha-momorcharin, a member of typical type I RIPs isolated from Momordica charantia, showed strongly antifungal, antitumor, and antibacterial activities both in vitro and in vivo. In this study, the expression level of alpha-momorcharin gene in response to environmental stress and phytohormones were examined through quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting analyses. Results showed that α-momorcharin gene expression was up-regulated in response to salinity and osmotic stresses. Phytohormones, including abscisic acid and gibberellic acid, also enhanced α-momorcharin expression, while the expression level was not affected by salicylic acid. It’s speculated that the α-momorcharin gene might be functional in plant basal or defense resistance against environmental stresses, and it also involved in hormonal signaling pathways. This research might be exploited in further genetic engineering programs and plant protection.