EN
The changes in endogenous proline levels of Raphanus sativus L. seedlings was monitored in presence of exogenous amino acids in normal and osmotically stressed seedlings. In unstressed seedlings, proline uptake was detected only at higher (1 mM) concentration of applied L-proline. however, proline uptake was promoted at all (1 µM to 1000 µM) concentrations of applied L-proline under osmotic stress conditions. Amongst other exogenous amino acids, L-leucine, L-glutamic acid, L-alanine, and L-histidine enhanced endogenous levels of proline, while exogenous hydorxyproline and γ-amino butyric acid reduced it.