Table II.

Total in vitro GS activity and concentrations of NH4 + and selected amino acids in leaves of 6-week-old wild-type and GS2-antisense oilseed rape

PlantTotal GS ActivityPhotorespirationTissue [NH4+]Amino Acids
GluGlnGlySer
μmol g−1fresh wt h−1 μmol m−2s−1 μm μm
Wild type74.7 ±  13.4  (100%)1.65 ±  0.46530 ±  46910 ±  59528 ±  1692 ±  16283 ±  5
Antisense17.9 ±  1.1  (24%)1.98 ±  0.37548 ±  471,253 ±  09681 ±  9492 ±  3305 ±  6

Values are means of four to six replicates ± se. Total leaf N was 4.6% ± 0.3% and leaf nitrate was 0.75 ± 0.05 mm in tissue water of both wild-type and antisense plants.