Effect of salinity and water stress on nitrogen metabolism in Sesbania grandiflora (L.) Poir

The nitrate nitrogen and total nitrogen contents decreased due to water as well as salt stresses. Nitrite nitrogen content decreased with increasing concentration of salt salinity, while it was accumulated under water stress conditions. The accumulation of insoluble protein nitrogen was more in the leaves under water stress conditions, but, decreased in the stem. The free amino acids and amide contents were affected due to salinity stress than the water stress. The activity of nitrate reductase was inhibited by salinity treatments in leaves, roots and nodules. On the contrary, its activity increased under water stress conditions. Nitrite reductase in leaves was inhibited, while got stimulated in the roots and nodules due to salinity stress. However, reverse pattern was observed under water stress conditions.