Table I. Maximum catalytic activities of enzymes of carboxylic acid metabolism in fruit of wild-type and transgenic tomato plants expressing an antisense aconitase construct.
Tomatoes harvested at 40 and 55 DAA were extracted, and the maximal catalytic activities of six enzymes of carboxylic acid metabolism were measured. The wild type and two independent transgenic lines (ACO19 and ACO38) were assessed. Each value is the mean ± se of six biological replicates. Values significantly different from the wild type are indicated in boldface (Student’s t test, P < 0.05).
| Enzyme Activity |
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|---|---|---|---|---|---|---|
| Enzyme | 40 DAA |
55 DAA |
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| Wild Type | ACO19 | ACO38 | Wild Type | ACO19 | ACO38 | |
| nmol min−1 g−1 fresh wt | ||||||
| Aconitase | 20.1 ± 5.3 | 13.1 ± 3.4 | 12.5 ± 3.9 | 32.5 ± 4.8 | 24.7 ± 3.9 | 22.6 ± 6.1 |
| Succinate dehydrogenase | 0.73 ± 0.12 | 0.87 ± 0.09 | 0.77 ± 0.14 | 1.03 ± 0.15 | 0.93 ± 0.06 | 0.89 ± 0.10 |
| Fumarase | 190 ± 32.3 | 202 ± 25.7 | 182 ± 28.6 | 150 ± 22.3 | 135 ± 15.7 | 143 ± 18.7 |
| NAD+-malate dehydrogenase | 3521 ± 145 | 3152 ± 188 | 3698 ± 132 | 1024 ± 89 | 896 ± 110 | 963 ± 138 |
| Citrate synthase | 11.3 ± 1.8 | 10.8 ± 1.5 | 9.7 ± 1.5 | 5.3 ± 1.7 | 4.3 ± 1.9 | 5.8 ± 1.9 |
| NADP-isocitrate dehydrogenase | 22.5 ± 2.5 | 20.8 ± 3.6 | 18.9 ± 4.4 | 60.5 ± 5.8 | 62.5 ± 7.7 | 55.5 ± 6.9 |