The effects of sodium chloride, potassium chloride and glycerol on the activity of nitrate reductase of a salt-tolerant and two non-tolerant plants.

The activity of nitrate reductase from the salt-tolerant alga Dunaliella parva is inhibited by sodium chloride and potassium chloride, but not by glycerol. The activity of the enzyme from Chlorella pyrenoidosa Chick 611-8b and from the XD line of tobacco (Nicotiana tabacum L. cv. Xanthi) cells is inhibited by all three solutes. Salt tolerance in Dunaliella parva, which is due to internal formation of glycerol, is accompanied by the adaptation of the activity of the enzyme to elevated glycerol concentrations.