Table 2.

Summary of pairwise OPLS-DA computation for shoot and root metabolic fingerprints acquired with UPLC-TOF-MS of control, aphid-, nematode-, and aphid + nematode-treated plants at 3 days after infestation

Comparison	MD	R2X(cum)	R2Y(cum)	Q2(cum)	F	P
Shoot
C vs. A	1+3	0.612	0.985	0.646	3.16	0.038
C vs. N	nm
C vs. AN	1+0	0.384	0.399	0.235	2.61	0.102
A vs. N	nm
A vs. AN	nm
N vs. AN	nm
Root
C vs. A	1+1	0.218	0.465	0.157	1.58	0.234
C vs. N	nm
C vs. AN	nm
A vs. N	1+4	0.630	0.990	0.577	1.92	0.157
A vs. AN	1+6	0.757	0.939	0.501	0.90	0.563
N vs. AN	nm

There were 10 replicates per treatment (data are shown from one representative experiment of three independent experiments). The quality of the resulting models was evaluated with the routine 1/7th out cross validation based on the residuals with R²X(cum) (cumulative modelled variation in X), R²Y(cum) (cumulative modelled variation in Y), and Q²cum (model predictive ability parameter according to cross validation). The result from CV-ANOVA based on the cross-validated predictive residuals is listed for each model and significant results (indicating a valid model) are marked by bold numbers. MD = model dimensions (predictive + orthogonal components); nm = no model could be generated; C = control; A = aphid treatment; N = nematode treatment; AN = aphid + nematode treatment.