Table 2. List of metabolites detected in ray cells and tracheids using picoPPESI-MS in negative ion mode.
Asterisks indicate significant differences between the ray cells (RC) and tracheids (TR) as follows: *, P < 0.05 and ***, P < 0.001.
| Metabolite | Molecular Formula | Ion Type Detected | Theoretical m/za | Signal Intensity | P | Relative Abundanceb | P | Frequency of Detectionc | MS/MS Results Shown in | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| RC | TR | RC | TR | RC | TR | |||||||
| Monolignol pathways | ||||||||||||
| Cinnamic acid or p-Coumaraldehyde | C9H8O2 | [M−H]− | 147.045 | 3.9.E+04 | 1.4.E+05 | 0.359 | 0.019 | 0.034 | 0.416 | ++++ | ++++ | |
| p-Coumaric acid | C9H8O3 | [M−H]− | 163.040 | 4.1.E+04 | 5.0.E+04 | 0.749 | 0.015 | 0.024 | 0.416 | +++++ | ++++ | Supplemental Figure S3A.1 |
| 4-Coumaroyl-CoA | C30H38N7O18P3S | [M−H]− | 912.145 | – | – | – | – | – | – | – | – | |
| Caffeoyl-CoA | C30H42N7O19P3S | [M−H]− | 928.140 | – | – | – | – | – | – | – | – | |
| Feruloyl-CoA | C31H44N7O19P3S | [M−H]− | 942.155 | – | – | – | – | – | – | – | – | |
| Caffeic acid | C9H8O4 | [M−H]− | 179.035 | 1.0.E+05 | 2.7.E+05 | 0.392 | 0.045 | 0.168 | 0.353 | +++++ | ++++ | Supplemental Figure S3A.2 |
| Caffeoylshikimic acid | C16H16O8 | [M−H]− | 335.077 | – | – | – | – | – | – | – | – | |
| Caffeoylquinic acid | C16H18O9 | [M−H]− | 353.088 | 1.1.E+04 | 9.3.E+03 | 0.912 | 0.005 | 0.006 | 0.956 | ++ | ++ | |
| Coniferyl aldehyde | C10H10O3 | [M−H]− | 177.056 | 3.0.E+04 | 1.2.E+05 | 0.184 | 0.015 | 0.041 | 0.101 | ++++ | +++++ | Supplemental Figure S3A.3 |
| Coniferyl alcohol | C10H12O3 | [M−H]− | 179.071 | 1.1.E+06 | 1.5.E+06 | 0.705 | 0.527 | 0.446 | 0.717 | +++++ | +++++ | Supplemental Figure S3A.4 |
| p-Coumaryl alcohol | C9H10O2 | [M−H]− | 149.061 | 1.0.E+04 | 4.4.E+04 | 0.033 | 0.005 | 0.023 | 0.050 | +++ | ++++ | Supplemental Figure S3A.5 |
| Coniferin | C16H22O8 | [M−H]− | 341.124 | 1.5.E+05 | 1.3.E+05 | 0.872 | 0.055 | 0.029 | 0.451 | +++ | +++ | Supplemental Figure S3A.6 |
| Coniferin | C16H22O8 | [M+Cl]− | 377.101 | 5.9.E+06 | 2.6.E+06 | 0.296 | 2.415 | 1.239 | 0.368 | +++++ | ++++ | Supplemental Figure S3A.7 |
| p-Coumaryl alcohol 4-glucoside | C15H20O7 | [M−H]− | 311.114 | 1.3.E+04 | 2.7.E+03 | 0.480 | 0.004 | 0.002 | 0.656 | + | + | Supplemental Figure S3A.8 |
| p-Coumaryl alcohol 4-glucoside | C15H20O7 | [M+Cl]− | 347.090 | 1.0.E+05 | 5.3.E+04 | 0.494 | 0.043 | 0.027 | 0.611 | ++++ | +++ | Supplemental Figure S3A.9 |
| Dihydroconiferin | C16H24O8 | [M−H]− | 343.140 | – | – | – | – | – | – | – | – | |
| Dihydroconiferin | C16H24O8 | [M+Cl]− | 379.117 | – | – | – | – | – | – | – | – | |
| Shikimate and aromatic amino acid pathways | ||||||||||||
| Phosphoenolpyruvic acid | C3H5O6P | [M−H]− | 166.975 | 2.7.E+04 | 4.5.E+04 | 0.373 | 0.014 | 0.019 | 0.575 | ++++ | ++++ | |
| d-Erythrose 4-phosphoric acid | C4H9O7P | [M−H]− | 199.001 | 5.0.E+04 | 6.0.E+04 | 0.833 | 0.033 | 0.020 | 0.625 | ++++ | ++++ | Supplemental Figure S3A.10 |
| 3-Dehydroquinic acid | C7H10O6 | [M−H]− | 189.041 | 3.2.E+05 | 8.9.E+05 | 0.134 | 0.137 | 0.363 | 0.079 | +++++ | +++++ | Supplemental Figure S3A.11 |
| Shikimate-3-phosphoric acid | C7H11O8P | [M−H]− | 253.012 | – | – | – | – | – | – | – | – | |
| 5-Enolpyruvylshikimate | C10H13O10P | [M−H]− | 323.017 | – | – | – | – | – | – | – | – | |
| 3-Phosphoric acid (EPSP) | ||||||||||||
| Chorismic acid and prephenic acid | C10H10O6 | [M−H]− | 225.041 | 6.1.E+02 | 1.5.E+04 | 0.208 | 0.0004 | 0.004 | 0.172 | ++ | ++ | Supplemental Figure S3A.12 |
| Flavonoid pathways | ||||||||||||
| Flavanone | C15H12O2 | [M−H]− | 223.077 | – | – | – | – | – | – | – | – | |
| Sakuranetin or isosakuranetin | C16H14O5 | [M−H]− | 285.077 | – | – | – | – | – | – | – | – | |
| Dihydroflavonols | C15H12O3 | [M−H]− | 239.071 | 5.3.E+03 | 3.2.E+04 | 0.373 | 0.003 | 0.006 | 0.582 | +++ | ++ | |
| Leucocyanidin or melacacidin | C15H14O7 | [M−H]− | 305.067 | – | – | – | – | – | – | – | – | |
| Leucodelphinidin | C15H14O8 | [M−H]− | 321.062 | 7.2.E+03 | 1.4.E+04 | 0.571 | 0.003 | 0.009 | 0.448 | +++ | ++ | |
| Leucofisetinidin or leucopelargoni din | C15H14O6 | [M−H]− | 289.072 | – | – | – | – | – | – | – | – | |
| Leucopeonidin | C16H18O7 | [M−H]− | 321.098 | – | – | – | – | – | – | – | – | |
| Organic acids | ||||||||||||
| Malic acid | C4H6O5 | [M−H]− | 133.014 | 6.7.E+07 | 1.6.E+08 | 0.067 | 29.866 | 72.346 | 0.001*** | +++++ | +++++ | |
| Quinic acid | C7H12O6 | [M−H]− | 191.056 | 2.2.E+08 | 2.0.E+08 | 0.739 | 100.000 | 84.992 | 0.071 | +++++ | +++++ | |
| Oxaloacetic acid | C4H4O5 | [M−H]− | 130.999 | 7.5.E+03 | 5.6.E+05 | 0.152 | 0.002 | 0.332 | 0.152 | +++ | +++ | |
| Succinic acid | C4H6O4 | [M−H]− | 117.019 | 1.5.E+06 | 1.9.E+06 | 0.619 | 0.683 | 0.770 | 0.743 | +++++ | +++++ | |
| Ascorbic acid | C6H8O6 | [M−H]− | 175.025 | 4.7.E+06 | 5.8.E+06 | 0.679 | 2.385 | 2.654 | 0.828 | +++++ | +++++ | |
| 3-Phosphoglyceric acid | C3H7O7P | [M−H]− | 184.986 | 2.9.E+05 | 3.5.E+05 | 0.606 | 0.146 | 0.181 | 0.555 | +++++ | +++++ | |
| α-Ketoglutaric acid | C5H6O5 | [M−H]− | 145.014 | 4.1.E+05 | 6.8.E+05 | 0.197 | 0.170 | 0.354 | 0.084 | +++++ | +++++ | |
| Fumaric acid | C4H4O4 | [M−H]− | 115.004 | 1.7.E+06 | 3.5.E+06 | 0.160 | 0.751 | 1.525 | 0.029* | +++++ | +++++ | |
| Citric acid | C6H8O7 | [M−H]− | 191.020 | 4.1.E+06 | 2.4.E+07 | 0.021* | 2.052 | 12.433 | 0.040* | +++++ | +++++ | |
| Carbohydrate | ||||||||||||
| Hex | C6H12O6 | [M−H]− | 179.056 | 5.5.E+06 | 6.0.E+06 | 0.716 | 2.454 | 2.776 | 0.523 | +++++ | +++++ | |
| Hex | C6H12O6 | [M+Cl]− | 215.033 | 1.3.E+07 | 1.6.E+07 | 0.761 | 5.927 | 8.840 | 0.549 | +++++ | +++++ | |
| Hex2 | C12H22O11 | [M−H]− | 341.109 | 1.1.E+07 | 1.1.E+07 | 0.967 | 5.847 | 4.506 | 0.528 | +++++ | +++++ | |
| Hex2 | C12H22O11 | [M+Cl]− | 377.086 | 2.7.E+06 | 4.0.E+06 | 0.546 | 1.161 | 2.521 | 0.292 | +++++ | +++++ | |
| Pentose | C5H10O5 | [M−H]− | 149.046 | 5.4.E+06 | 6.0.E+06 | 0.812 | 2.394 | 2.382 | 0.982 | +++++ | +++++ | |
| Pentose | C5H10O5 | [M+Cl]− | 185.022 | 5.9.E+03 | 4.2.E+04 | 0.039 | 0.003 | 0.023 | 0.075 | + | ++++ | |
| Amino acids | ||||||||||||
| Ser | C3H7NO3 | [M−H]− | 104.035 | 5.4.E+04 | 5.1.E+04 | 0.911 | 0.033 | 0.021 | 0.499 | +++++ | ++++ | |
| Pro | C5H9NO2 | [M−H]− | 114.056 | 2.9.E+05 | 1.8.E+05 | 0.578 | 0.164 | 0.056 | 0.239 | +++++ | +++ | |
| Val | C5H11NO2 | [M−H]− | 116.072 | 1.6.E+05 | 1.4.E+05 | 0.793 | 0.087 | 0.057 | 0.500 | +++++ | ++++ | |
| Thr | C4H9NO3 | [M−H]− | 118.051 | 1.9.E+05 | 1.6.E+05 | 0.676 | 0.102 | 0.078 | 0.516 | +++++ | +++++ | |
| Leu, Ile | C6H13NO2 | [M−H]− | 130.087 | 3.0.E+05 | 2.1.E+06 | 0.335 | 0.156 | 1.911 | 0.334 | +++++ | ++++ | |
| Asp | C4H8N2O3 | [M−H]− | 131.046 | 1.2.E+05 | 1.2.E+05 | 0.978 | 0.073 | 0.036 | 0.453 | ++++ | ++++ | |
| Asp | C4H7NO4 | [M−H]− | 132.030 | 1.0.E+06 | 9.6.E+05 | 0.875 | 0.604 | 0.485 | 0.708 | +++++ | +++++ | |
| Gln | C5H10N2O3 | [M−H]− | 145.062 | 2.1.E+06 | 1.3.E+06 | 0.472 | 1.090 | 0.409 | 0.196 | +++++ | +++++ | |
| Glu | C5H9NO4 | [M−H]− | 146.046 | 9.9.E+05 | 1.1.E+06 | 0.752 | 0.513 | 0.537 | 0.920 | +++++ | +++++ | |
| Met | C5H11NO2S | [M−H]− | 148.044 | 1.0.E+04 | 3.6.E+03 | 0.567 | 0.005 | 0.001 | 0.430 | + | + | |
| His | C6H9N3O2 | [M−H]− | 154.062 | 8.3.E+04 | 7.7.E+04 | 0.916 | 0.041 | 0.025 | 0.448 | ++++ | +++++ | |
| Phe | C9H11NO2 | [M−H]− | 164.072 | 1.1.E+05 | 2.4.E+05 | 0.368 | 0.053 | 0.108 | 0.418 | +++++ | +++++ | |
| Arg | C6H14N4O2 | [M−H]− | 173.104 | 2.7.E+04 | 7.9.E+03 | 0.242 | 0.018 | 0.003 | 0.153 | +++ | ++ | |
| Tyr | C9H11NO3 | [M−H]− | 180.067 | 1.1.E+05 | 1.1.E+05 | 0.998 | 0.057 | 0.028 | 0.410 | ++++ | ++++ | |
| Trp | C11H12N2O2 | [M−H]− | 203.083 | 8.3.E+04 | 1.2.E+05 | 0.711 | 0.053 | 0.032 | 0.624 | ++++ | ++++ | |
| GABA | C4H9NO2 | [M−H]− | 102.056 | 7.5.E+04 | 4.1.E+04 | 0.405 | 0.040 | 0.015 | 0.171 | +++++ | ++++ | |
| Peptide | ||||||||||||
| Glutathione | C10H17N3O6S | [M−H]− | 306.077 | 6.1.E+05 | 8.1.E+05 | 0.645 | 0.313 | 0.317 | 0.979 | +++++ | +++++ | |
| Terpenoids | ||||||||||||
| Abietic acid | C20H30O2 | [M−H]− | 301.217 | 7.7.E+06 | 7.7.E+06 | 0.996 | 4.071 | 4.575 | 0.921 | +++++ | ++++ | |
| α-Pinene | C10H16 | [M−H]− | 135.118 | – | – | – | – | – | – | – | – | |
| Cluster ions | ||||||||||||
| Malic acid + Hex | C10H18O11 | [M−H]− | 313.078 | 6.6.E+05 | 9.0.E+06 | 0.219 | 0.290 | 2.258 | 0.069 | +++++ | +++++ | |
| Malic acid + Hex2 | C16H28O16 | [M−H]− | 475.130 | 2.4.E+06 | 4.1.E+06 | 0.286 | 1.093 | 2.474 | 0.152 | +++++ | +++++ | |
| Quinic acid + Hex | C13H24O12 | [M−H]− | 371.119 | 2.6.E+07 | 2.4.E+07 | 0.858 | 10.529 | 12.679 | 0.666 | +++++ | +++++ | |
| Quinic acid + Hex2 | C19H34O17 | [M−H]− | 533.172 | 3.1.E+07 | 1.7.E+07 | 0.298 | 11.558 | 9.478 | 0.686 | +++++ | +++++ | |
| Coniferin + Hex | C22H34O14 | [M−H]− | 521.188 | 1.3.E+05 | – | 0.337 | 0.039 | – | 0.323 | ++ | — | |
| Coniferin + Hex2 | C28H44O19 | [M−H]− | 683.240 | 1.3.E+05 | 1.0.E+05 | 0.852 | 0.041 | 0.019 | 0.528 | ++ | ++ | |
| Malic acid + coniferin | C20H28O13 | [M−H]− | 475.146 | 1.7.E+05 | 2.8.E+03 | 0.325 | 0.052 | 0.001 | 0.306 | ++ | + | |
| Quinic acid + coniferin | C23H34O14 | [M−H]− | 533.188 | 2.1.E+06 | 5.5.E+05 | 0.360 | 0.733 | 0.272 | 0.432 | +++ | ++ | |
a
All the theoretical values are quoted from Metlin (http://metlin.scripps.edu/index.php).
b
Values were calculated as a percentage of the base peak.
c
Signal detected (+); signal not detected (−). Frequencies of detection (x) in eight to nine individual measurements are indicated as follows: +++++, 80% < x < 100%; ++++, 60% < x < 80%; +++, 40% < x < 20%; ++, 20% < x < 40%; +, 0% < x < 20%.