Brassinosteroids (BRs) are plant hormones widely distributed throughout the plant kingdom in low concentrations and with structural homology to animal and insect steroids. BRs are involved in numerous physiological processes. The effect of 24-epibrassinolide (EBL) and 28-homobrassinolide (HBL) on the metabolites content of radish (Raphanus sativus) subjected to water (osmotic) stress being imposed by polyethylene glycol was studied. Brassinosteroids supplementation under desiccation stress was associated with elevated levels of soluble proteins, nucleic acids and carbohydrates. Brassinosteroids also enhanced the accumulation of the osmolyte free proline in radish seedlings challenged with drought stress. The results of present study demonstrate the protective role of brassinosteroids against PEG imposed water stress in radish seedlings.
