Early effects of salinity on nitrate assimilation in soybean (Glycine max L cv. Pershing) seedlings

In the present study, the effects of NaCl (100, 150 and 200mm) on nitrate assimilation in Soybean (Glycine max L. cv. Pershing) seedlings was studied. In vivo. Based on the results of this study, salinity affects nitrate uptake more than its reduction, and in different concentrations, these effects are not identical. Treatments 150 and 200Mm influence on the induction phase of nitrate uptake, but 100mM treatment, affects uptake rate only. There is a decrease in nitrate efflux from secondary root tip slices of seedlings that were in Hoagland solutions (one third concentration,during 24 hours) with different concentrations of NaCl, for 150 and 200 mM treatments, that may reflect the changes in the structure of root cells membranes. Regarding the effects of salinity on nitrate reduction, it seems that in spite of inducive type of nitrate reductase, the constitutive type is affected by salinity, significantly.