Table II.

Effects of leaf aging on the activity of the enzymes of nitrogen metabolism in transgenic tobacco plants, which harbor the GLU1 promoter of the Arabidopsis Fd-Glu synthase fused to a GUS reporter gene (GLU1::GUS)

Enzyme assays were carried out in two transgenic lines: GLU1GUS*1 and GLU1GUS*2.

Nitrogen Metabolism EnzymesYoung LeavesOld Leaves
GLU1GUS*1GLU1GUS*2GLU1GUS*1GLU1GUS*2
Enzyme activity: nmol mg−1 protein min−1
NR15.50 ± 1.4018.76 ± 2.064.70 ± 0.404.67 ± 0.42
GS90.50 ± 8.21102.27 ± 11.2522.67 ± 2.0134.00 ± 3.10
Fd-GOGAT16.17 ± 1.4821.51 ± 2.114.50 ± 0.385.81 ± 0.55
NADH-GOGAT0.33 ± 0.030.41 ± 0.040.11 ± 0.010.14 ± 0.02
NADH-GDH
    Aminating33.77 ± 3.1431.07 ± 3.0178.50 ± 7.2176.12 ± 8.37
    Deaminating14.17 ± 1.2813.89 ± 1.8121.33 ± 1.9819.51 ± 2.15