Table 2.
Activity of Smirnoff Pathway Enzymes in Courgette Vascular Exudate and Tissue
| Activitya | Phloem | Tissue |
| HK (D-Glc) | 23.0 ± 1.73 | 22.5 ± 2.89 |
| HK (D-Frc) | 29.7 ± 1.33 | 24.8 ± 3.58 |
| HK (D-Man) | 4.0 ± 0.40 | 4.0 ± 0.58 |
| PGI | 1861.3 ± 15.18 | 1194.7 ± 173.38 |
| PMI | 94.2 ± 5.20 | N.D.b |
| PMM | 1.5 ± 0.11 | N.D.b |
| GDPM PPase | 22.8 ± 1.56 | N.D.b |
| GDPM-3,5-epimerase | 0.07 ± 0.012 | 0.12 ± 0.017 |
| GDP-L-gal PPPase | 0.012 + 0.002 | 0.010 ± 0.002 |
| L-GalDH | 28.0 ± 0.46 | 7.0 ± 1.27 |
| L-GalLDH | N.D.b | 1.98 ± 0.18 |
a Activity is expressed in nmol min-1 gFW-1 of tissue ± S.E., n = 3 b N.D. = Activity not detected Courgette fruit exudate or tissue was prepared and desalted as described in the text. Enzymes listed are: HK, hexokinase (E.C. 2.7.1.1) with D-glucose (D-Glc), D-fructose (D-Frc) or D-mannose (D-Man) as substrate; PGI, phosphoglucose isomerase (E.C. 5.3.1.9); PMI, phosphomannose isomerase (E.C. 5.3.1.8); PMM, phosphomannose mutase (E.C. 5.4.2.8); GDPM PPase, GDP-D-mannose pyrophosphorylase (E.C. 2.7.7.22); GDPM-3,5-epimerase, GDP-D-mannose-3,5-epimerase (E.C. 5.1.3.18); GDP-L-gal PPPase, GDP-L-galactose pyrophosphatase; L-GalDH, L-galactose dehydrogenase; L-GalLDH, L-galactono-1,4-lactone dehydrogenase (E.C. 1.3.2.3). Where no E.C. numbers are supplied they have yet to be assigned.