Table 3.
Putatively-identified root metabolites exhibiting robust changes in response to ethylene.
| Metabolite | EMRT | Method | Average log two-fold change after transfer to hormone-containing medium | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 0.5 h | 1 h | 2 h | 4 h | 8 h | 12 h | 24 h | |||
| Glucosinolates | |||||||||
| 4-methylsulfinylbutyl glucosinolate | 73.32_436.0403 | RP-Neg | −2.7 | −1.6 | −1.2 | −2.1 | 1.5 | 4.7 | −3.8 |
| 7-methylsulfinylheptyl glucosinolate | 374.59_478.0873/238.06_478.0875 | RP-Neg/HILIC-Neg | −2.8 | −1.5 | −1.1 | −1.3 | 2.2 | 2.2 | −4.8 |
| 8-methylsulfinyloctyl glucosinolate | 432.65_492.103/230.65_492.1032 | RP-Neg/HILIC-Neg | −3.0 | −1.7 | −1.2 | −1.4 | 2.6 | 3.2 | −6.0 |
| 4-methylthiobutyl glucosinolate | 233.56_420.0453 | RP-Neg | −2.3 | −2.6 | −1.5 | −2.3 | 1.5 | 4.0 | −6.8 |
| 5-methylthiopentyl glucosinolate and hydroxy-8-methylsulfinyl octyl glucosinolate (isomer a) | 284.19_434.061 | RP-Neg | −1.9 | −2.4 | −1.3 | −1.6 | 1.2 | 2.1 | −4.2 |
| hydroxy-8-methylsulfinyl-octyl glucosinolate (isomer b) | 244.53_508.098 | RP-Neg | −3.6 | −1.5 | −1.2 | −1.2 | 2.6 | 2.0 | −3.5 |
| 7-methylthioheptyl glucosinolate | 399.01_462.0926 | RP-Neg | −1.6 | −1.7 | −1.0 | −1.5 | 1.3 | 2.4 | −4.7 |
| 8-methylthiooctyl glucosinolate | 454.6_476.1082 | RP-Neg | −1.6 | −1.6 | −1.1 | −1.4 | 1.0 | 1.9 | −4.5 |
| 4-benzoyloxy N-butyl glucosinolate | 379.81_494.0789 | RP-Neg | −1.4 | −2.8 | −1.3 | −1.7 | 1.5 | 3.1 | −5.9 |
| N-methoxyglucobrassicin | 340.76_477.0637 | RP-Neg | −2.2 | −2.7 | −1.4 | −1.1 | 1.5 | 2.8 | −5.4 |
| Phenylpropanoids | |||||||||
| N,N-9-di(sinapoyl)-spermidine | 165.11_558.281 | HILIC-Pos | 2.5 | 1.5 | −1.4 | 1.3 | 1.4 | −1.2 | −1.1 |
| quercetin hexose hexose* | 258.76_625.1406 | RP-Neg | 1.7 | 1.7 | 2.2 | 1.2 | 2.1 | 1.8 | −1.0 |
| quercetin-containing unknown | 432.71_835.2083 | RP-Neg | 1.9 | 2.6 | 2.7 | 1.3 | 2.9 | 2.3 | −1.1 |
| kaempferol deoxyhexose deoxyhexose* | 354.4_577.1557 | RP-Neg | 2.0 | 1.4 | 1.3 | −1.1 | 3.0 | 1.4 | 1.4 |
| kaempferol hexose deoxyhexose deoxyhexose* | 327.01_739.2083 | RP-Neg | 1.4 | 1.2 | 2.4 | 1.1 | 2.8 | 2.6 | 1.6 |
| G(8-O4)S(8-5)FA hexose | 474.1_759.25 | RP-Neg | 1.2 | 1.4 | −1.2 | 1.7 | 2.0 | 2.5 | −1.4 |
| hexose G(8-O-4)FA malate + 238 | 495.4_789.2605 | RP-Neg | 1.1 | 1.2 | −1.1 | 1.1 | 2.2 | 2.5 | −1.3 |
| hexose G(8-O-4) FA malate + 238 | 470.52_789.2605 | RP-Neg | 1.4 | 1.4 | −1.1 | 1.3 | 2.3 | 2.6 | −1.4 |
| Indole-containing metabolites | |||||||||
| IAA hexose* | 306.41_336.1079 | RP-Neg | 3.2 | −1.3 | −1.6 | 2.4 | −1.3 | −1.3 | −3.8 |
| Fatty acids | |||||||||
| trihydroxyhexadecanoic acid hexose* | 481.27_465.2694 | RP-Neg | 2.9 | 2.4 | 3.6 | 3.4 | −1.0 | −1.2 | −1.2 |
Included are all metabolites with features that differed ≥ 2 fold relative to the time-matched control in all three biological replicates at one or more sampling times; values that meet these criteria are shown in bold and are underlined. Values are the average fold change for the three replicates, with positive numbers indicating elevated levels and negative numbers indicating reduced levels relative to the untreated controls. Putative identifications are based on fragmentation patterns obtained by MS/MS and MSE, with further details available in Table S1. Asterisks identify the five metabolites common to the auxin and ethylene datasets. RP = reversed phase; HILIC = hydrophilic interaction chromatography. Standard abbreviations are used for oligolignols, with G, S, and FA = guaiacyl units, syringyl units, and ferulic acid, respectively.