Abstract:In order to improve the application stability and biological activity of Brassinolide (BR), reduce its use loss and make it release slowly, in this study, ethylene glycol diglycidyl ether (EGDE), ethylenediamine-terminated Polyethyleneimine (PEI-EDA), and glycine betaine (GB) were used to modify Zein to load BR(BR@ AM-Zein-GB). The structure and morphology of the modified products were characterized by Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). The drug-loaded nanoparticles with an average particle size of 174 nm were prepared by the anti-solvent method. The encapsulation efficiency and drug loading capacity of BR were 45.59% and 17.53 ug/mg, respectively. The sustained release of drug-loaded nanoparticles in different ethanol water contents was evaluated. The results showed that the maximum sustained release of BR@ AM-Zein-GB was obtained at 60% ethanol aqueous solution by volume. Being soaked in 0.100 mh/L-BR@$ AM-Zein-GB, the germination of cucumber seed was the best under salt stress (120 mmol/L NaCl). Which showed that BR@AM Zein GB had stable biological activity and controlled release ability.