Two cucumber varieties,'Changchun Mici'(with strong salt resistance) and 'Jinchun 2'(with weak salt resistance) were hydroponically cultured to study the effects of salt stress on proline and polyamine metabolisms in the roots of cucumber seedlings.It was shown that salt stress could increased △~1-pyrroline-5-carboxylate synthase(P5CS) activity and inhibited proline dehydrogenase(ProDH) activity,thus increasing the proline content in the roots of cucumber seedlings,the variations in 'Changchun Mici' were si...