Abstract: The effects of sulfur and 6-Benzyladeine on the nitrate reductase activity in rice seedlings were studied by the water culture method. The activity of nitrate reductase was decreased, when plants were grown in sulfur deficient solution. Both sulfur deficient plant and the control were treated in nutrient solution with 6-Benzyladenine concentration of 0.01, 0.1 or 1ppm. It was found that the nitrate reductase activity of former plant was increased, while the activity of the latter one was decreased. When the plants were treated in untrient solution with 6-Benzyladenine concentration of 1 ppm, the transformation of inorganic sulfur to organic compounds was markedly increased in the sulfur deficient plant. However it was decreased in control plant.

Key words: Sulfur, 6-Benzyladenine, Rice seedings, The nitrate reductase activity