© 1991 Heron Publishing—Victoria, Canada
Effects of nitrate on in vivo nitrate reductase activity of seedlings from three open-pollinated families of Robinia pseudoacacia
Kurt H. Johnsen (1, 2), Bruce C. Bongarten (1) and Lindsay R. Boring (1)
1. School of Forest Resources, The University of Georgia, Athens, Georgia 30602, USA / 2. Forestry Canada, Petawawa National Forestry Institute, Chalk River, Ontario, Canada K0J 1J0 / Received October 15, 1990
Summary
In vivo NO3– reductase activity (NRA) was determined in eight- and nine-week-old nodulated seedlings from three open-pollinated families
of black locust (Robinia pseudoacacia L.) that were grown in sand culture and fertilized with 0, 0.5, 1.0, 5.0, or 15.0 mM NO3–. Nitrate reductase activity was induced by NO3–. Unlike many temperate legumes, enzymatic activity was typically much higher in leaves than in roots. This may have energetic
ramifications because of the potentially lower energy costs of NO3– reduction in leaves than in roots.
