Effect of Salt Stress on Nitrate Reductase Activity in Some Leguminous Crops

The effects of increasing levels of NaCl and Na₂CO₃ (0, 4, 8 and 12 dSm⁻¹) on nitrate reductase activities (NRA) in Lentil (Lens esculentum L.), Chickpea (Cicer arietinum L.) and Pea (Pisum sativum L.) were studied. Salt stress caused a marked reduction in NRA in both root and shoot parts. NRA in shoot was inhibited to a greater extent than in the roots and Na₂ CO₃ inhibited more than NaCl. On the other hand, a foliar spray with triacontanol [CH₃ (CH₂)₂₈ CH₂OH] in nanomolar concentrations stimulated NRA in both parte of the plants. This enhancement was attributed to the capacity of triacontanol to induce enzyme activity.