Response of wheat and maize to different nitrogen sources: II. Nitrate reductase and glutamine synthetase enzyme activities, and plastid pigment content

Abstract

Abstract Glutamine synthetase and nitrate reductase enzyme activities occurred both in roots and leaves of maize (Zea mays L., hybrid Pioneer 3737) and wheat (Triticum aestivum L., cultivar Jantar) plants grown on different nitrogen (N) sources. Enzyme activities and plastid pigment content in maize plants were higher in the treatments with a mixture of nitrate (NO3) and ammonium (NH4) than with either N source alone. In wheat plants, plastid pigment content, nitrate reductase activity, and root glutamine snynthetase activity were higher in the treatments where NO3 alone was applied to the nutrient medium.