Table 1.

Metabolites displaying differential abundance between root exudates collected from Fe-sufficient and Fe-deficient microcuttings of Ramsey and 140R rootstocks at 3 and 6 h.

Compound	% variation	p-value	VIP
Ramsey Fe+ vs. Ramsey Fe−; 3 h
Increased abundance
l-glutamate	16,160.03	0.004	2.19
Cyclolariciresinol	8.19	0.0393	1.74
Caprylic acid	61.19	0.0498	1.71
Decreased abundance
Campesteryl ferulate	19.36	0.0169	2
140R Fe+ vs. 140R Fe−; 3 h
Increased abundance
3-Sinapoylquinic acid	6.25	0.0016	1.85
p-Coumaric acid-4-O-glucoside	5.07	0.0022	1.80
Apigenin 6-C-glucoside	5.57	0.0042	1.75
2-Methoxy-5-prop-1-enylphenol	18.17	0.0086	1.66
Cyclolariciresinol	9.94	0.0074	1.65
Avenanthramide 2f.	5.79	0.0114	1.64
1-Acetoxypinoresinol	5.56	0.0111	1.62
Isoxanthohumol	5.31	0.0194	1.53
5-Heneicosenylresorcinol	9.74	0.0256	1.49
Caffeic acid ethyl ester	10.29	0.026	1.48
Benzoxazinone	7.63	0.0273	1.47
l-histidine	11.16	0.0458	1.40
l-ascorbate	54.86	0.04	1.38
Gallic acid ethyl ester	6.14	0.0492	1.33
Decreased abundance
Campesteryl ferulate	45.32	0.0408	1.42
Schottenol ferulate	13.52	0.0381	1.41
Ramsey Fe+ vs. Ramsey Fe−; 6 h
Increased abundance
l-glutamate	63,740.98	< 0.0001	2.50
Maltose/sucrose	216.50	0.0043	2.00
l-tyrosine	242.13	0.0074	1.98
Homoveratric acid	52.02	0.0209	1.76
Decreased abundance
Sakuranetin	60.09	0.0352	1.71
4-Hydroxycoumarin	6.93	0.0462	1.66
140R Fe+ vs. 140R Fe−; 6 h
Increased abundance
l-glutamate	25,186.35	< 0.0001	2.17
Caffeic acid 4-O-glucoside	82.92	0.0049	1.79
Maltose/sucrose	98.31	0.0047	1.77
Wighteone	15.30	0.0073	1.74
Episesamin	15.30	0.0073	1.74
3,4 Dihydroxyphenyl-2-oxypropanoic acid	35.43	0.0101	1.69
2-Methoxy-5-prop-1-enylphenol	8.36	0.0165	1.60
2-Hydroxybenzoic acid	5.37	0.0253	1.52
l-methionine	67.82	0.0429	1.46
Decreased abundance
Campesteryl ferulate	11.19	0.0302	1.55

The percentage increase or decrease, p-value for t-test and VIP value from OPLS-DA are reported for each compound.