Table 4.
Frequency of Correlations between Enzymes and Metabolites in the Same Metabolic Sequence
| Total Matrix |
Defined Metabolic Segment |
|||||
| Number of Significant Correlations | Total No. of Metabolite-Enzyme Comparisons | % of Significant Correlations | No. of Correlations between Enzymes and Metabolites | No. of Possible Enzyme-Metabolite Pairs | % of Significant Correlations | |
| Calvin-Benson cycle and carbohydrates | 1 | 520 | 0.2 | 0 | 24 | 0 |
| Starch synthesis | 0 | 161 | 0 | 0 | 2 | 0 |
| Sucrose metabolism | 3 | 347 | 0.9 | 0 | 5 | 0 |
| Hexose metabolism | 0 | 297 | 0 | 0 | 9 | 0 |
| Nitrogen assimilation | 1 | 421 | 0.2 | 0 | 15 | 0 |
| Aminotransferases | 0 | 309 | 0 | 0 | 10 | 0 |
| Aromatic amino acid synthesis | 1 | 272 | 0.4 | 0 | 8 | 0 |
| Malate and fumarate metabolism | 1 | 260 | 0.4 | 0 | 6 | 0 |
Several sets of enzymes and metabolites were identified in which the metabolites are the immediate or near-immediate substrates or products of enzymes: starch synthesis (pPGI, AGP, and starch), sucrose metabolism (cPGI, UGP, SPS, SuSy, INV, and sucrose), hexose metabolism (INV, GK, FK, sucrose, glucose, and fructose), nitrogen assimilation (NR, GS, GOGAT, NAD-IDH, NADP-ICDH and Gln, and 2-oxoglutarate and Glu), central amino transferase reactions (AspAT, AlaAT and Glu, 2-oxoglutarate, pyruvate, Asp, and Ala), aromatic amino acid synthesis (TK, shikimateDH, shikimate, Phe, Trp, and Tyr), and malate and fumarate metabolism (NAD-MDH, NADP-MDH, fumarase, malate, and fumarate). The six Calvin-Benson cycle enzymes were also compared with starch, sucrose, glucose, and fructose. For each set identified, all significant (pBH < 0.01) correlations were between enzyme-metabolite pairs in the trait set. This is compared with the number of correlations that these traits have in the data matrix without the initial activities.