Table II.

SPS activities in leaves of the three genotypes of transgenic tobacco plants

SPS activities were determined in leaf samples of 6-week-old plants. Samples were taken 5 h into the light period. SPS activity was measured under both optimal (Vmax) and limiting (Vsel) assay conditions. The control (*) plants were grown alongside with NtSPSAi transgenic tobacco plants, and the control (**) plants were grown alongside with NtSPSCi and chiSPSi transgenic tobacco plants. Data represent the mean (±sd) of determinations on six individual plants per line.

Plant LineSPS Activity (μmol min−1 m−2)
VmaxVselVsel/Vmax
%
Control*24.8 ± 4.25.4 ± 1.521.4 ± 2.4
NtSPSAi2819.7 ± 2.65.2 ± 1.226.0 ± 3.5
NtSPSAi4123.7 ± 5.34.4 ± 1.118.1 ± 3.1
NtSPSAi6219.2 ± 4.45.8 ± 1.525.5 ± 3.7
Control**33.3 ± 2.59.2 ± 0.427.7 ± 1.5
NtSPSCi929.4 ± 1.87.5 ± 0.725.4 ± 2.7
NtSPSCi2032.6 ± 2.18.1 ± 0.824.9 ± 2.6
NtSPSCi3527.3 ± 0.77.3 ± 0.526.7 ± 1.4
chiSPSi821.0 ± 1.56.0 ± 0.528.7 ± 1.7
chiSPSi2720.6 ± 1.75.9 ± 0.728.5 ± 1.8
chiSPSi3019.7 ± 1.05.7 ± 0.428.9 ± 1.4