Salinity-induced effects on nitrogen assimilation related to growth in cowpea plants

摘要: Abstract This study was carried out to establish relationships between nitrate and ammonia assimilation growth of cowpea (Vigna unguiculata (L.) Walp) plants when exposed NaCl-salinity. Cowpea were initially pre-acclimated under a mild NaCl-stress (50 mol m−3) during 8 days in order induce salt acclimation. Subsequently, non-acclimated received NaCl-osmotic shock (100 the nutrient solution for 4 days. Although exhibited lower NO3− uptake rate, situ reduction, reductase (NR) activity, shoot growth, they did not show alterations these parameters, expressed as % control, time-course experiment. These data suggest adaptative response NaCl-salt stress. In contrast, addition high level NaCl induced steady decrease parallel reduction particularly salt-shock applied on plants. On other hand, leaf glutamine synthetase free amino acids proline concentration showed slight increase all treatments. The soluble protein slightly reduced by treatments short-term exposure. Moreover, with concentrations compared Our indicates that regulation processes N acquisition do operate at whole plant resulting homeostasis, especially mild-salt Furthermore, leaf-NR activity are more limiting than primary from synthetase.