Table I.

Enzyme activity in SCoAL transgenic lines

Activity was determined in 6-week-old fully expanded source leaves. Data presented are mean ± se of determinations on six individual plants per genotype. Values set in bold type were determined by the t test to be significantly different (P < 0.05) from the wild type. –, Not measured; AGPase, ADP-Glc pyrophosphorylase; UGPase, UDP-Glc pyrophosphorylase; GDH, Glu dehydrogenase.

EnzymeActivity
Wild TypeAL18RL40RL25
nmol min−1 g−1 FW
AGPase507 ± 68591 ± 64792 ± 177602 ± 61
UGPase8.48 ± 1.28.64 ± 0.94.81 ± 1.23.97 ± 1.0
PFK ATP dependent69.9 ± 6.194.9 ± 7.778.7 ± 7.965.5 ± 2.0
PFK PPi dependent0.21 ± 0.050.19 ± 0.040.28 ± 0.030.16 ± 0.03
NADP-GAPDH0.83 ± 0.070.54 ± 0.031.02 ± 0.150.30 ± 0.12
Pyruvate kinase1.55 ± 0.151.45 ± 0.11.67 ± 0.181.46 ± 0.12
Rubisco3.67 ± 0.552.31 ± 0.482.79 ± 0.332.94 ± 0.80
Transketolase4.14 ± 0.453.40 ± 0.493.42 ± 0.623.43 ± 0.81
Phosphoribulokinase1.62 ± 0.182.29 ± 0.222.79 ± 0.232.02 ± 0.26
Phosphoglyceratekinase0.87 ± 0.180.99 ± 0.121.29 ± 0.110.60 ± 0.11
GDHa313.6 ± 41.6413.3 ± 87.2556.5 ± 109.2
GADb0.99 ± 0.091.23 ± 0.131.60 ± 0.07
  • a Rubisco and GDH activity values are presented as μmol min−1 g−1 FW.

  • b GAD activity values are presented as 14CO2 (as a % of 14C supplied) min−1 mg−1 protein.